Question

find the area of this triangle​

Answer 1

Concept :

In order to find the area of the shades triangle, we will use the formula of triangle. Firstly we will find the area of whole right angled triangle and then we will subtract the area of non shaded traingle.

Formula used :

Area of triangle = 1/2 × Base × Height

Solution :

❒ Area of whole triangle :-

Area of ∆ = 1/2 × Base × Height

Area of ∆ = 1/2 × (15 cm) × ( 12 cm + 8 cm)

Area of ∆ = 1/2 × 15 cm × 20 cm

Area of ∆ = 15 cm × 10 cm

Area of ∆ = 150 cm²

❒ Area of unshaded triangle :-

Area of ∆ = 1/2 × Base × Height

Area of ∆ = 1/2 × 15 cm × 8 cm

Area of ∆ = 15 cm × 4 cm

Area of ∆ = 60 cm²

Now from subtracting area of unshaded triangle from the area of whole triangle will give us the area of shaded triangle.

❒ Area of shaded triangle :-

Area of ∆ = 150 cm² - 60 cm²

Area of ∆ = 90 cm²

• So the required area of triangle is 90 cm².