WAEC - Mathematics (2022 - No. 28)
In the diagram, MNR is a tangent to the circle centre O at N and ∠NOS = 108°. Find ∠OSN
72°
32°
36°
18°
Paskaidrojums
The sum of angles in a triangle = 180º
(180 - 108)º = 72º
Isosceles triangle has both two equal sides and two equal angles.
∠OSN = ∠SON = \(\frac{72}{2}\)
= 36º