## Chapter 15 Area Set 15.4

∴ The area of the triangle is 756 sq.cm.

Question 2.

Look at the measures shown in the given figure and find the area of ☐PQRS.

= 270 sq.m

In ∆PSR, m∠PSR = 90°

[l(PR)]² = [l(PS)]² + [l(SR)]²

…[Pythagoras theorem]

= (36)² + (15)²

= 1296 + 225

∴ l(PR)² = 1521

∴ l(PR) = 39m

…[Taking square root of both sides]

In ∆PQR, a = 56m, b = 25m, c = 39m

A(☐PQRS) = A(∆PSR) + A(∆PQR)

= 270 + 420

= 690 sq. m

∴ The area of ☐PQRS is 690 sq.m

Question 3.

Some measures are given in the figure, find the area of ☐ABCD.

∴ The area of ☐ABCD is 570 sq.m.