UI Post-UTME Mathematics 2023 (Model questions) Question 2

Question 2

Mensuration of Plane Shapes

If the radius of a circle is triples, by what factor does the area increase?

  1. A.3
  2. B.6
  3. C.9
  4. D.12
Show the answer and explanation

Answer: C (9)

Explanation

Area is proportional to r²; tripling r multiplies the area by 3² = 9.