Page 202 - Touchpad Mathematics_Ver1.0_C5

E:\Working\Orange_Education\TouchPad_Maths-5\Open file\Chap-08 Folder
\ 19-Nov-2025 Bharat Arora Proof-9 Reader’s Sign _______________________ Date __________

11. Find the number of square tiles, each of side 15 cm, required to cover the floor of a
room of length 6 m and breadth 3 m.
12. Find the area of a rectangle whose length is 24 m and perimeter is 88 m.

13. Find the area of a square whose perimeter is 120 m.

AreA oF A triANGLe

Look at the square given alongside.

Area of the square = 6 cm × 6 cm = 36 sq. cm
A diagonal divides the square into two halves. Each half

is a triangle.
Thus, the area of a triangle is half the area of the square.

Area of each triangle = (36 ÷ 2) sq. cm = 18 sq. cm

Is this also true for a rectangle? Let us see.

Here, a rectangle with a length of 12 cm and a
breadth of 8 cm is given.

Area of the rectangle = 12 cm × 8 cm = 96 sq. cm

Again, a diagonal divides the rectangle into
two equal halves and each half is a triangle.

So, area of each triangle = (96 ÷ 2) sq. cm
= 48 sq. cm.

example 1. Find the area of the following triangles:

a. b.

Solution.

Step 1. Draw a rectangle around the triangle as shown.
a. b.

200 Mathematics 5