passwella.
Menu

WAEC Mathematics 2010 Question 34

Question 34

Mensuration of Plane Shapes

In the diagram, |EF| = 8 cm, |FG| = x cm, |GH| = (x + 2) cm, ∠EFC = 90°. If the area of the shaded portion is 40 cm2, find the area of ΔEFG.

Diagram for this question
  1. A.128 cm2
  2. B.72 cm2
  3. C.64 cm2
  4. D.32 cm2
Show the answer and explanation

Answer: D (32 cm2)

Explanation

Shaded ΔEGH has base x + 2 and height 8: ½ × 8 × (x + 2) = 40, so x = 8. Area of ΔEFG = ½ × 8 × 8 = 32 cm2.