JAMB Mathematics 2018 Paper

Given length of the room = 12m; breadth = 9m and height = 8m.

The room is a cuboid in shape, therefore the length of the diagonal = $\sqrt{l^2 + b^2 + h^2}$

= $\sqrt{12^2 + 9^2 + 8^2}$

=$\sqrt{289}$

= 17m.

The diagonal makes an angle with the diagonal of the floor: $\sqrt{12^2 + 9^2}$

= $\sqrt{225}$

= 15m

The cosine of the angle that the diagonal makes with the floor ($\theta$) = $\frac{15}{17}$.