Question

In the following figure, find the area of the shaded portion:

Answer 1

Answer:

150

Step-by-step explanation:

area of square = 20 *20 = 400

subtract the area of  outer right angled triangles

area of 1st outer triangle = 1\2*10*20 = 100

area of 2nd outer triangle = 1\2*10*10= 50

area of 3rd outer triangle = 1\2*10*20=100

area of shaded region = 400-100-50-100 = 250

Answer 2

Formula

Area of Δ = 1/2 × b × h

Area of Δ PQT

Area = 1/2 × PT × PQ

        = 1/2 × 10 × 20

        = 5 × 20

        = 100

Area of Δ SUT

Area = 1/2 × ST × SU

        = 1/2 × 10  × 10

        = 5 × 10

        = 50

Area of Δ QUR

Area = 1/2 × UR × QR

        = 1/2 × 10 × 20

        = 5 × 20

        = 100

Area of PQRS

Area = side × side

        = 20 × 20

        = 400

Area of Δ QUT

Area = Area of PQRS - ( Area of Δ PQT + Δ QUR + Δ SUT )

        = 400 - ( 100 + 50 + 100 )

        = 400 - 250

        = 150

ANSWER :

The area of the shaded portion is 150 cm²