What is the value of x?
5
3 8 7

All angles in a triangle add up to 180

180 = 9 + 15 + 2x - 1 + 3x

180 = 24 - 1 + 2x + 3x

180 = 23 + 5x

180 - 23 = 5x

157 = 5x

Divide both sides by 5

X = 31.4 or 157/5

Trigonometry is The branch of mathematics concerned with specific functions of angles and their application to calculations. There are six functions of an angle commonly used in trigonometry. Their names and abbreviations are sine (sin), cosine (cos), tangent (tan), cotangent (cot), secant (sec), and cosecant (csc).Formula

The trigonometry formulas for trigonometry ratios when the angles are in addition are given as, sin(x + y) = sin(x)cos(y) + cos(x)sin(y) cos(x + y) = cos(x)cos(y) - sin(x)sin(y) tan(x + y) = (tan x + tan y)/(1 - tan x • tan y) .

Hope this helps you !!