Question

What is the area of the shaded region below?
с
90°
А
B
12 cm

Answer 1

≈ 41.1 cm²

Explanation:

The shaded area (A) is calculated as

A = area of sector - area of Δ ABC

= πr² ×
`(90)/(360)` - (
`(1)/(2)` × 12 × 12 )

= π × 12² ×
`(1)/(4)` - (6 × 12)

= 144π ×
`(1)/(4)` - 72

= 36π - 72

≈ 41.1 cm² ( to 1 dec. place )