Question

which represents an exterior angle of triangle abf?
∠bad
∠afe
∠cad
∠cab

Explanation:

An exterior angle of a triangle is formed by one side of the triangle and the extension of an adjacent side.

• $\angle BAD$: It is an exterior angle of triangle $ABF$ as it is formed by side $AB$ of $\triangle ABF$ and the extension of side $AF$ (since $AD$ is an extension).
• $\angle AFE$: It is not related to the sides of $\triangle ABF$ in the exterior - angle - forming way.
• $\angle CAD$: It has no relation to the sides of $\triangle ABF$.
• $\angle CAB$: It has no relation to the sides of $\triangle ABF$.

Answer:

$\angle BAD$