WAEC Mathematics 2023 Paper

Concept:For a square, the diagonal forms a right-angled triangle with two sides.Using Pythagoras theorem, we can find the area directly as $l^2$.Explanation:Let each side of the square be $l$.Then the area of the square is $l^2$.Using Pythagoras theorem on the right triangle formed by two sides and the diagonal:$l^2 + l^2 = 12^2$$2l^2 = 144$Divide both sides by 2:$l^2 = 72$So the area of the square is $72 \, \text{cm}^2$.Answer:$72 \, \text{cm}^2$Option C.