Answer:
Step-by-step explanation:
Notice that all three sides of the given triangle has one tick mark.
This means that all three sides are congruent, meaning that we have an equilateral triangle.
And for equilateral triangles, all three angles are also congruent.
So:
Also, recall that the interior angles of a triangle is always 180. Thus:
Substitute:
Combine like terms:
Substitute:
Multiply:
Thus:
And we are done!