What is the measure of Angle C

59

Step-by-step explanation:

(2x-1)+(3x+1)+x=180

6x=180

x=30

((2×30)-1)= 59

This is a good illustration of what's wrong with trigonometry.  The carpenter has nice exact legs and we're being asked to turn into an inexact angle by a weirdly notated function that looks like a reciprocal but isn't.

Never mind.   Tangent is opposite over adjacent, which here is riser over tread,

 C. arctan(6/11)