Answer:
75 degrees
Step-by-step explanation:
The two marks on the triangle sides mean they are the same length (congruent). Because of the Isosceles Triangle Theorem, the angles across from those two congruent sides are also congruent. That means that angle C also measures 3x. Because all the sides of a triangle add up to equal 180, then (x+5) + 3x + 3x = 180. 7x + 5 = 180, and 7x = 175. That means that x = 25. Take that 25 and sub it into 3x to get 3(25) = 75 degrees.
