Question

Calculate the area of trap. PQRS, given in Fig.

Answer 1

From the figure

Using the Pythagoras theorem in △ RTQ

We get

RT² + TQ² = RQ²

By substituting the values

RT² + 8² = 17²

On further calculation

RT² = 17² – 8²

So we get

RT² = 289 – 64

By subtraction

RT² = 225

By taking square root

RT = √ 225

RT = 15cm

We can find the area of trapezium

Area of trapezium PQRS = ½ (sum of parallel sides × distance between them)

So we get

Area of trapezium PQRS = ½ ((8 + 16) × 15)

On further calculation we get

Area of trapezium PQRS = 180 cm²

Therefore, the area of trapezium PQRS is 180 cm².