Question

177 25 Marks

Rajesh is working out the area of a circle with radius 10.
He writes:
Area = 3.142 x 20
Explain why Rajesh's working is wrong.

Answer 1

Rajesh did πr2 (π × r × 2) instead of πr². The correct work would be

Area = 3.142 x 10² so... Area = 3.142 x 100 not 3.142 x 20.