NECO 2023 · Paper 1 · Q42

Angles, triangles & polygons

Determine the value of $7x$ in the diagram (an isosceles triangle with apex angle $5x$ and base angles $2x$ ).

Worked solution (try it first)

The angles of a triangle add up to $180^\circ$ : $5x + 2x + 2x = 180^\circ$ .
So $9x = 180^\circ$ and $x = 20^\circ$ .
Then $7x = 7 \times 20^\circ = 140^\circ$ , option E.

Report a problem with this question