Question

If one of the exterior angles of a triangle is acute, then the triangle must be

acute
right
obtuse
equiangular

Answer 1

Answer: Third option is correct.

Explanation:

If one of the exterior angles of a triangle is acute then,

By using the rule of "Linear Pair" we can find the interior angle

Let the exterior angle be

`80\textdegree`

So, its interior angle be

`180-80=100\textdegree`

So, our triangle become obtuse triangle .

So, we can take any measure of acute angle , always we get an obtuse angle .

Hence, Third option is correct.

Answer 2

If one of the exterior angles of a triangle is acute, then the related interior angle must be obtuse.
Answer: The triangle must be C ) obtuse.