Question

In a triangle LMN, ∠= (3x +15)⁰ , ∠M = 30⁰,and ∠N = (4x ‒5)⁰. Find the value of x , ∠L and ∠N

Answer 1

Sum of all angles of ∆ is 180°

So,

angle L + angle N + angle M = 180°

3x + 15 + 4x - 5 + 30° = 180°

7x + 10 = 180° - 30°

7x = 150 - 10

7x = 140

x = 20

therefore angle L is 3(20)+15 = 65°

angle N = 4(20)-5 = 75°