Richmond Y. answered 05/30/19
Patient Math Tutor for all ages
Klauss,
I would first write an equation to help solve this problem.
The sum of all angles of a triangle is 180 degrees so we can write an equation as follows.
given:m∠A=(3x)°, m∠B=(x+5)°, and m∠C=(x−15)°
3x + (x+5) + (x-15) = 180
3x +x +x +5 - 15 = 180
5x - 10 = 180
5x = 190
x = 38
m∠A=(3x)° = 3(38)o 114o
m∠B=(x+5)° = (38+5)o = 43o
m∠C=(x−15)° = (38-15)o = 23o
Answer: A, 114o
I hope this helps.
Please feel free to reach me if you still need clarification.
Thanks,
Richmond