Answer:
83.5
Step-by-step explanation:
x + 4x + 5x -13 =180 The sum of the interior angles of a triangle is 180
10x - 13 = 180 Combine like terms
10x = 193 Add 13 to both sides
x = 19.3 degrees.
Substitute 19.3 for x in the expression for C
5x -13
5(19.3) -13
83.5
