Answer:
The value of x is 9°
Step-by-step explanation:
The given parameters are;
ΔUVW with side UW extended to X
m∠UVW = (3x + 4)°
m∠VWX = (8x -12)°
m∠WUV = (x + 20)°
We have that m∠UVW + m∠WUV + m∠VWU = 180° (Sum of the interior angles of a triangle theorem)
∴ m∠VWU = 180° - (m∠UVW + m∠WUV)
Also we have that m∠VWX and m∠VWU are supplementary angles, (The sum of angles on a straight line)
∴ m∠VWX + m∠VWU = 180° (Definition of supplementary angles)
m∠VWU = 180° - m∠VWX
∴ m∠VWX = (m∠UVW + m∠WUV)
Substituting the values, gives;
(8x -12)° = (3x + 4)° + (x + 20)°
8x - 3x - x = 4 + 20 + 12
4x = 36
x = 36/4 = 9
x = 9°.
