Question

In the triangle, what is the degree measure of angle ABC ?

Answer 1

m∠ABC = 110°

Explanation:

There is an exterior angle given, at about point C. This can be utilized to find the interior angle, as they form a linear pair and ergo are supplementary. So,

180° - 135° = 45°

∠C = 45°

Now, you know that a triangle contains 180°. So, use ∠A + ∠B + ∠C = 180° to find the missing angle.

25° + ∠B + 45° = 180°

70° + ∠B = 180°

∠B = 110°

∠B in this case can also be written as ∠ABC.