write and solve an equation to find the measure of the unknown angle.

Step-by-step explanation:
Here, x+ 45° = 180° (Sum of linear pair)
or, x= 180° - 45°
So, x= 135°
Answer:
Let x be the measure of the unknown angle.
Since the sum of angles in a triangle is 180°, we can write the equation:
45° + 60° + x = 180°
Solving for x:
105° + x = 180°
x = 180° - 105°
x = 75°
Therefore, the measure of the unknown angle is 75°.