Answer:
m∠ABC = 110°
Step-by-step 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.
