Expressions for the measures of the angles of a triangle are shown in the diagram below.
Which of the following equations would be used to find the value of x?
A . 2x + 15 + x + 20 = 3x + 25
B . 3x + 25 + 2x + 15 = x + 20
C . 3x + 25 + x + 20 = 2x + 15
D . 3x + 25 + 2x + 15 + x + 20 = 360
E . 3x + 25 + 2x + 15 + x + 20 = 180
Answer: E