A circle has a radius of 21 metres.
Work out an estimate for the area of the circle.
Hence, work out an estimate for the area of a semicircle with the same radius.
Is your answer to part (a) an underestimate or an overestimate? Give a reason for your answer.
247 exam-style questions on Eduqas GCSE Maths Estimating. Each one has a worked solution and a mark scheme showing where the marks go.