The answer is 10 because all the angles are equal making it a equilateral triangle.
Therefore, the sides are all equal to one another, 3x - 8 = 5x - 20.
You just solve for x and get 6. You then plug in 6 for x and evauluate the equation, getting 10.
2(10+5)−5
=(2)(15)−5
=30−5
=25
C is the answer.
The answer is 110.
The 55 degree angle is related to arc B. The measure of arc B is double the measure of the angle. So, arc B covers 55*2=110 degrees.
Answer:

Step-by-step explanation:
-This is an addition/subtraction problem.
#We subtract the sum of the first two expression from the third expression:

Hence, the expression
must be added to the first two.
Base angles.
They are congruent