Answer:
Part 1) the value of x is
Part 2)

Part 3)

Explanation:
Part 1)
Find the value of x
we know that
The sum of the internal angles of a triangle must be equal to

so
In this problem

substitute the values

solve for x
Part 2) Find the measure of angle B

substitute the value of x

Part 3) Find the measure of angle C

substitute the value of x
