Answer:
x = 75
Step-by-step explanation:
1. Find the inner angle (opposite from where x is), using the outer angle of 150.
Note: these two angles are supplementary, meaning that they add up to 180 degrees.
Since the outer angle is 150, the inner angle is 30 degrees because 150+30 = 180.
2. Find the other two angles to get x.
The red markings on the two sides of the triangle indicate that this is an isocoleses triangle. Isocoleses triangles have two congruent angles. This means that the remaining two angles will be the same.
With that in mind, recall what I said about the angles being supplementary. All angles in a triangle add up to 180. So, use the following equation and solve for x.
2x + 30 = 180 (Subtract 30 from both sides)
2x = 150 (divide by 2)
x = 75
3. x = 75
