Answer:
21
Step-by-step explanation:
We need to utilise one important angle in order to answer this question which is
→ Angles in a triangle add up to 180°
Using this information we can set up an equation to find the value of x
⇒ Form equation using the important angle fact
→ x - 4 + 3x + 100 = 180
⇒ Simplify the 'x' and the numerical terms
→ 4x + 96 = 180
⇒ Minus 96 from both sides to isolate 4x
→ 4x = 84
⇒ Divide both sides by 4 to isolate x
→ x = 21
The value of x is 21
