Kungfu math p4 slide18 (area)pdf

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Transcript of Kungfu math p4 slide18 (area)pdf

• concepts of area and perimeter of a plane figure

• measurement of area in square units

• measurement of area in square centimetres

What will we learn today?

Measurement Area

What is Area?

Area is the size of a surface.

Area of Simple Shapes

There are special formulas for certain shapes:

For example:

What is the area of this rectangle?

5cm

3cm

Area of Simple Shapes

There are special formulas for certain shapes:

For example:

What is the area of this rectangle?

Area = Length x Breadth

5cm

3cm

Area of Simple Shapes What is the area of this rectangle?

Area = Length x Breadth

Length is the longest dimension of an object.

5cm

3cm

Length

Area of Simple Shapes What is the area of this rectangle?

Area = Length x Breadth

Breadth is the extent or measure of how broad or wide something is.

5cm

3cm Breadth

Area of Simple Shapes What is the area of this rectangle?

Area = Length x Breadth

Length is the longest dimension of an object.

Breadth is the extent or measure of how broad or wide something is.

5cm

3cm

Length

Breadth

Area of Simple Shapes

Therefore, by applying the formula.

What is the area of this rectangle?

Area of rectangle = Length x Breadth

5cm

3cm

Area of Simple Shapes

Therefore, by applying the formula.

What is the area of this rectangle?

Area of rectangle = Length x Breadth

= 5cm x 3cm

5cm

3cm

Area of Simple Shapes

Therefore, by applying the formula.

What is the area of this rectangle?

Area of rectangle = Length x Breadth

= 5cm x 3cm

= 15 cm²

5cm

3cm

Area of Simple Shapes

Therefore, by applying the formula.

What is the area of this rectangle?

Area of rectangle = Length x Breadth

= 5cm x 3cm

= 15 cm²

5cm

3cm

Notice the difference in units?

Area of Simple Shapes

Therefore, by applying the formula.

What is the area of this rectangle?

Area of rectangle = Length x Breadth

= 5cm x 3cm

= 15 cm²

The unit for AREA is cm² or m²

Summary

You can only find area when the length and breadth have the same units.

For example,

the length is 5 cm and the breadth is 4 cm.

The area will be 20 cm².

Summary

You can only find area when the length and breadth have the same units.

For example,

the length is 5 m and the breadth is 4 m.

The area will be 20m².

The area of Square T is 45cm² smaller than the area of Square P.

Find the edge of Square Q.

P Q

Area = 81cm²

The area of Square T is 45cm² smaller than the area of Square P.

Find the edge of Square Q.

P Q

81 – 45 = 36 cm²

Area = 81cm²

The area of Square T is 45cm² smaller than the area of Square P.

Find the edge of Square Q.

P Q

6 x 6 = 36 cm²

Area = 81cm²

6cm

6cm

The area of Square T is 45cm² smaller than the area of Square P.

Find the edge of Square Q.

P Q

The edge of Square Q is 6cm.

Area = 81cm²

6cm

6cm

The perimeter of a rectangular plot of land is 32m. Its length is 9m. Find its area.

Step 1: Find the breadth.

Area = ? cm²

9m

?m

The perimeter of a rectangular plot of land is 32m. Its length is 9m. Find its area.

Step 1: Find the breadth. 32 - 9 – 9 = 14 m

14 ÷ 2 = 7 m

Area = ? cm²

9m

?m

The perimeter of a rectangular plot of land is 32m. Its length is 9m. Find its area.

Step 2: Find the area. 9 x 7 = 63m²

Area = ? cm²

9m

7m

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