Perimeter, area and units of measure

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Units of Measure

Length is measured in millimetres (mm), centimetres (cm), metres (m), and kilometres (km).
1 cm = 10 mm, 1 m = 100 cm, 1 km = 1000 m.
Mass is measured in grams (g) and kilograms (kg). 1 kg = 1000 g.
Capacity (how much liquid a container holds) is measured in millilitres (ml) and litres (l). 1 l = 1000 ml.
Time is measured in seconds (s), minutes (min), and hours (h). 1 min = 60 s, 1 h = 60 min.
To convert from a larger unit to a smaller unit, multiply. For example, 3 m = 3 × 100 = 300 cm.
To convert from a smaller unit to a larger unit, divide. For example, 5000 g = 5000 ÷ 1000 = 5 kg.

Perimeter of Polygons

The perimeter is the total distance around a shape.
For any polygon (a flat shape with straight sides), add the lengths of all its sides to find the perimeter.
A rectangle has two lengths (l) and two widths (w). Its perimeter is P = 2 × l + 2 × w.
You can also write the rectangle perimeter as P = 2 × (l + w).
A square is a rectangle with all four sides equal. If one side is s, then P = 4 × s.
For a shape made from rectangles, split it into rectangles, find the missing side lengths, then add all the outside edges.

Area

Area is the amount of space inside a flat shape.
Area is measured in square units, like square centimetres (cm²) or square metres (m²).
You can find area by counting squares on a grid. Each full square counts as 1 unit.
For a rectangle, area = length × width, written as A = l × w.
For a square, area = side × side, written as A = s × s or A = s².
Remember: perimeter is the distance around, area is the space inside.

Telling Time

An analogue clock has two hands: the short hand shows hours, the long hand shows minutes.
On an analogue clock, each number represents 5 minutes. For example, if the minute hand points to 3, it is 15 minutes past the hour.
A digital clock shows time as numbers, like 3:45.
The 24-hour clock uses numbers from 00:00 to 23:59. For example, 3:45 PM is 15:45.
To find a duration (how long something lasts), subtract the start time from the end time. For example, from 2:30 to 4:15 is 1 hour and 45 minutes.
When subtracting times, you may need to borrow 60 minutes from the hour. For example, 4:15 - 2:30 = 3:75 - 2:30 = 1:45.

Solving Word Problems

Read the problem carefully and underline the question.
Identify what you need to find: perimeter, area, or time.
Look for key words: 'around' or 'fence' often mean perimeter; 'inside' or 'cover' often mean area.
Check that units are the same before calculating. Convert if needed.
For perimeter problems, add all sides or use the rectangle formula.
For area problems, multiply length by width.
Always write the correct unit in your answer, like cm, cm², or minutes.

Perimeter of a Circle (Circumference)

The perimeter of a circle is called the circumference.
The diameter (d) is the distance across a circle through its centre.
The radius (r) is the distance from the centre to the edge. It is half the diameter: r = d ÷ 2.
The circumference is about 3 times the diameter. The exact number is π (π), which is about 3.14.
So the formula is C = π × d or C = 2 × π × r.
For example, if a circle has a diameter of 10 cm, its circumference is about 3.14 × 10 = 31.4 cm.

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1.What is the perimeter of a shape?
Easy
- AThe distance around the shape
- BThe space inside the shape
- CThe length of one side
- DThe width of the shape
2.Which unit would you use to measure the perimeter of a football field?
Easy
- Ameters
- Bsquare meters
- Cliters
- Dgrams
3.The perimeter of a circle is called its circumference.
Easy
True or false?
4.A square has side length 6 m. What is its perimeter?
Medium
- A12 m
- B24 m
- C36 m
- D18 m
5.Which of the following are units of length? (select all that apply)
Easy
- Akilometer
- Bkilogram
- Ccentimeter
- Dmilliliter
- Emeter
6.Match each shape to its perimeter formula.
Medium
- Rectangle
- Square
- Triangle
- 2 × (length + width)
- 4 × side
- sum of all three sides
7.Put these lengths in order from shortest to longest: 5 cm, 1 m, 250 mm, 0.5 km.
Easy
- 5 cm
- 250 mm
- 1 m
- 0.5 km
8.A rectangular garden is 15 m long and 10 m wide. How much fencing is needed to go around it once?
Medium
- A25 m
- B50 m
- C150 m
- D100 m

Thêm câu hỏi

9.Match each unit to what it measures.
Easy
- meter
- gram
- liter
- second
- length
- mass
- capacity
- time
10.Put these units in order from smallest to largest: 1 cm, 1 m, 1 km, 1 mm.
Medium
- 1 mm
- 1 cm
- 1 m
- 1 km
11.Which of the following are true about perimeter? (select all that apply)
Medium
- APerimeter is the distance around a shape.
- BPerimeter is measured in square units.
- CThe perimeter of a circle is called its circumference.
- DPerimeter can be found by counting the squares inside a shape.
- EPerimeter of a rectangle is 2 × (length + width).
12.To find the perimeter of a polygon, you add the lengths of all its sides.
Easy
True or false?
13.A rectangle has a length of 9 cm and a width of 4 cm. What is its perimeter?
Medium
- A26 cm
- B36 cm
- C13 cm
- D18 cm
14.Which of these is the same as 3 meters?
Medium
- A300 centimeters
- B30 centimeters
- C3000 millimeters
- D0.3 kilometers
15.Which of the following are units of capacity? (select all that apply)
Medium
- Aliter
- Bmilliliter
- Cgram
- Dkilometer
- Ecentiliter
16.Put these measurements in order from shortest to longest: 1.5 m, 150 cm, 0.15 km, 1500 mm.
Medium
- 1500 mm
- 150 cm
- 1.5 m
- 0.15 km
17.A square has a side length of 9 m. What is its perimeter?
Medium
- A18 m
- B36 m
- C81 m
- D27 m
18.Which of the following is the same as 2.5 meters?
Easy
- A250 cm
- B25 cm
- C2500 mm
- D200 cm
19.A rectangular garden is 20 m long and 15 m wide. How much fencing is needed to go around it once?
Medium
- A35 m
- B70 m
- C300 m
- D140 m
20.The perimeter of a polygon is the distance around it.
Easy
True or false?
21.A rectangular garden is 12 m long and 8 m wide. The owner wants to put a fence around it, but leave a 2 m gap for a gate. How many meters of fencing are needed?
Medium
- A38 m
- B40 m
- C42 m
- D36 m
22.A rectangular field is 60 m long and 40 m wide. A fence is built around it, but there is a 5 m gate. What is the total length of the fence?
Medium
- A195 m
- B200 m
- C190 m
- D205 m
23.A rectangle has an area of 24 cm². Which of the following could be its length and width? (select all that apply)
Medium
- A6 cm and 4 cm
- B8 cm and 3 cm
- C12 cm and 2 cm
- D5 cm and 4 cm
- E10 cm and 2 cm
24.A rectangle with length 10 cm and width 6 cm has the same area as a rectangle with length 12 cm and width 5 cm.
Medium
True or false?
25.Match each measurement to the most appropriate unit.
Medium
- Length of a pencil
- Mass of a bag of sugar
- Capacity of a water bottle
- centimeters
- kilograms
- liters
26.Put these measurements in order from smallest to largest.
Medium
- 0.5 km
- 250 m
- 1500 cm
- 2 m
27.Which of these is the same as 4 kilometers?
Easy
- A4000 meters
- B400 meters
- C40 meters
- D4 meters
28.The perimeter of a rectangle is the sum of all its four sides.
Easy
True or false?
29.Which unit would you use to measure the mass of a watermelon?
Easy
- Akilograms
- Bliters
- Cmeters
- Dsquare centimeters
30.What is the perimeter of a regular hexagon with side length 4 cm?
Easy
- A24 cm
- B20 cm
- C16 cm
- D12 cm
31.Which of the following are true about area? (select all that apply)
Easy
- AIt is measured in square units.
- BIt is the distance around a shape.
- CIt is the amount of space inside a shape.
- DIt is found by multiplying length by width for a rectangle.
- EIt can be measured in liters.
32.Put these times in order from shortest to longest: 1 hour, 30 minutes, 45 seconds, 2 hours.
Easy
- 45 seconds
- 30 minutes
- 1 hour
- 2 hours
33.Match each shape to the formula for its area.
Easy
- Rectangle
- Square
- Triangle
- length × width
- side × side
- 1/2 × base × height
34.Which of these is the same as 2 liters?
Easy
- A2000 milliliters
- B200 milliliters
- C20 milliliters
- D2 milliliters
35.The perimeter of a regular pentagon is found by multiplying the side length by 5.
Easy
True or false?
36.Which of the following is the correct formula for the perimeter of a rectangle?
Easy
- AP = 2 × (length + width)
- BP = length × width
- CP = length + width
- DP = 4 × length
37.Which of the following are units of time? (select all that apply)
Easy
- Asecond
- Bminute
- Chour
- Dmeter
- Eliter
38.Put these measurements in order from smallest to largest: 0.5 kg, 750 g, 1.2 kg, 200 g.
Medium
- 200 g
- 0.5 kg
- 750 g
- 1.2 kg
39.The area of a rectangle is found by multiplying its length by its width.
Easy
True or false?
40.Match each shape to the correct perimeter formula.
Easy
- Rectangle
- Square
- Equilateral polygon
- 2 × (length + width)
- 4 × side
- number of sides × side length
41.A rectangle has length 8 cm and width 5 cm. What is its perimeter in centimeters?
Easy
42.Fill in the blank: 1 meter = ___ centimeters.
Easy
1 meter = ____ centimeters.
43.What is the perimeter of a rectangle with length 12 cm and width 7 cm? Write the number only.
Medium
44.A square has a side length of 7 m. What is its perimeter?
Medium
45.Fill in the blank: 1 kilogram = ___ grams.
Easy
1 kilogram = ____ grams.
46.What is the perimeter of a rectangle with length 6 cm and width 4 cm? Write your answer with units.
Medium
47.A rectangle has length 10 cm and width 4 cm. What is its perimeter?
Easy
48.Fill in the blank: 1 kilometer = ___ meters.
Easy
1 kilometer = ____ meters.
49.A rectangle has a length of 12 cm and a width of 8 cm. What is its area in square centimeters?
Medium
50.Fill in the blank: 3 liters = ___ milliliters.
Easy
3 liters = ____ milliliters.
51.A rectangle has an area of 48 cm² and a length of 8 cm. What is its width?
Medium
52.What is the perimeter of a rectangle with length 5 cm and width 3 cm? Write your answer with units.
Medium
53.Explain how to find the perimeter of a shape made from two rectangles joined together.
Hard
54.Explain the difference between perimeter and area.
Medium
55.A rectangle has length 8 cm and width 5 cm. What is its perimeter in centimeters?
Easy
- A23 cm
- B26 cm
- C32 cm
- D29 cm
56.A square has a side length of 7 m. What is its perimeter?
Medium
- A34 m
- B25 m
- C31 m
- D28 m
57.A rectangle has length 10 cm and width 4 cm. What is its perimeter?
Easy
- A34 cm
- B25 cm
- C31 cm
- D28 cm
58.A rectangle has a length of 12 cm and a width of 8 cm. What is its area in square centimeters?
Medium
- A116 cm²
- B106 cm²
- C86 cm²
- D96 cm²
59.A rectangle has an area of 48 cm² and a length of 8 cm. What is its width?
Medium
- A6 cm
- B7 cm
- C5 cm
- D8 cm

Ghi chú ôn tập

## Perimeter, Area and Units of Measure ### Perimeter - The **perimeter** is the distance around a shape. It is the length of the boundary that surrounds a 2D shape. - For a **rectangle** with **length** \(\ell\) and **width** \(w\), the perimeter is: \(P = 2\ell + 2w\). - For any **polygon** (a shape with straight sides), add up the lengths of all its sides. - The perimeter of a circle is called its **circumference**. It is \(P = \pi \times D\), where \(D\) is the diameter (the distance across the circle through the centre). ### Area - **Area** is the amount of space inside a 2D shape. It is measured in square units, like square centimetres (cm²) or square metres (m²). - For a rectangle, area = length × width: \(A = \ell \times w\). - You can also find area by counting the number of unit squares that fit inside the shape. ### Units of Measure - **Length**: millimetres (mm), centimetres (cm), metres (m), kilometres (km). - 10 mm = 1 cm, 100 cm = 1 m, 1000 m = 1 km. - **Mass**: grams (g) and kilograms (kg). 1000 g = 1 kg. - **Capacity**: millilitres (ml) and litres (l). 1000 ml = 1 l. - **Time**: seconds (s), minutes (min), hours (h). 60 s = 1 min, 60 min = 1 h. ### Telling Time and Durations - Read analogue clocks: the short hand shows hours, the long hand shows minutes. - 24-hour clock: after 12 noon, add 12 hours (e.g., 3 p.m. is 15:00). - To find a duration, subtract the start time from the end time. ### Problem Solving - Use the correct formula and units. - Check if you need to convert units first. - Draw a picture if it helps.

perimeter: The distance around a shape. It is the length of the boundary that surrounds a 2D shape.
area: The amount of space inside a 2D shape, measured in square units.
rectangle: A four-sided shape with four right angles. Opposite sides are equal.
length: The longer side of a rectangle, or the measurement of how long something is.
width: The shorter side of a rectangle, or the measurement of how wide something is.
polygon: A shape with straight sides, like a triangle, square, or rectangle.
circumference: The perimeter of a circle.
diameter: The distance across a circle through its centre.
pi (π): A special number about 3.14. It is used to find the circumference of a circle.
square unit: A unit for measuring area, like a square that is 1 cm by 1 cm (cm²).
millimetre (mm): A very small unit of length. 10 mm = 1 cm.
centimetre (cm): A unit of length. 100 cm = 1 m.
metre (m): A unit of length. 1000 m = 1 km.
kilometre (km): A unit of length for long distances. 1 km = 1000 m.
gram (g): A unit of mass. 1000 g = 1 kg.
kilogram (kg): A unit of mass. 1 kg = 1000 g.
millilitre (ml): A unit of capacity. 1000 ml = 1 l.
litre (l): A unit of capacity. 1 l = 1000 ml.
second (s): A very short unit of time. 60 s = 1 min.
minute (min): A unit of time. 60 min = 1 h.
hour (h): A unit of time. 1 h = 60 min.
analogue clock: A clock with hands that show hours and minutes.
24-hour clock: A way of telling time using numbers from 00:00 to 23:59.
duration: The amount of time between two events.

Thẻ ghi nhớ

What is the perimeter of a shape?

The perimeter is the distance around a shape. It is the total length of the boundary of a two-dimensional shape.

How do you find the perimeter of a rectangle?

Add up the lengths of all four sides. Or use the formula P = 2 × (l + w), where l is length and w is width.

What is the perimeter of a rectangle with length 8 cm and width 5 cm?

P = 2 × (8 + 5) = 2 × 13 = 26 cm.

What is the perimeter of a square with side length 6 cm?

A square has four equal sides, so P = 4 × 6 = 24 cm.

What is the perimeter of a triangle with sides 3 cm, 4 cm, and 5 cm?

Add all sides: 3 + 4 + 5 = 12 cm.

What is the perimeter of a polygon?

Add the lengths of all its sides. For any polygon, the perimeter is the sum of the lengths of its sides.

What is the perimeter of a shape made from rectangles?

Add the lengths of all the outer sides. You can break the shape into rectangles, find the missing side lengths, then add all the outside edges.

What is area?

Area is the amount of space inside a flat shape. It is measured in square units, like square centimeters (cm²) or square meters (m²).

How do you find the area of a rectangle?

Multiply the length by the width: A = l × w. For example, a rectangle 4 cm by 3 cm has area 12 cm².

What is the area of a rectangle with length 7 cm and width 2 cm?

A = 7 × 2 = 14 cm².

How do you find the area of a shape by counting squares?

Count the number of unit squares that fit inside the shape. Each square is one square unit (like 1 cm²).

What is the area of a square with side length 5 cm?

A = 5 × 5 = 25 cm².

What is the perimeter of a rectangle with length 10 cm and width 3 cm?

P = 2 × (10 + 3) = 2 × 13 = 26 cm.

What is the area of a rectangle with length 6 cm and width 4 cm?

A = 6 × 4 = 24 cm².

How many millimeters are in 1 centimeter?

10 millimeters (mm) = 1 centimeter (cm).

How many centimeters are in 1 meter?

100 centimeters (cm) = 1 meter (m).

How many meters are in 1 kilometer?

1000 meters (m) = 1 kilometer (km).

How many grams are in 1 kilogram?

1000 grams (g) = 1 kilogram (kg).

How many milliliters are in 1 liter?

1000 milliliters (ml) = 1 liter (l).

How many seconds are in 1 minute?

60 seconds = 1 minute.

How many minutes are in 1 hour?

60 minutes = 1 hour.

How many hours are in 1 day?

24 hours = 1 day.

What is the perimeter of a rectangle with length 12 cm and width 7 cm?

P = 2 × (12 + 7) = 2 × 19 = 38 cm.

What is the area of a rectangle with length 9 cm and width 3 cm?

A = 9 × 3 = 27 cm².

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