WAEC 2022 · Paper 1 · Q25

In the diagram, $\angle WZY$ and $\angle WYX$ are right angles. Find the perimeter of $WXYZ$ .

Worked solution (try it first)

Triangle $WZY$ is right-angled at $Z$ , so $WY = \sqrt{4^2 + 3^2} = 5$ cm.
Triangle $WYX$ is right-angled at $Y$ , so $WX = \sqrt{5^2 + 12^2} = 13$ cm.
The perimeter goes round the outside only: $WX + XY + YZ + ZW = 13 + 12 + 3 + 4 = 32$ cm, option B.