Answer:
m<K = 51°
m<L = 78°
m<M = 51°
Explanation:
Base angles of an isosceles ∆ are equal to each other, therefore,
m<M = m<K
Substitute
3x + 36 = 4x + 31
Collect like terms and solve for x
3x - 4x = -36 + 31
-x = -5
Divide both sides by -1
x = 5
Let's find each degree measure using the value of x
m<K = 4x + 31
Plug in the value of x
m<K = 4(5) + 31
m<K = 20 + 31
m<K = 51°
m<M = 3x + 36
= 3(5) + 36
= 15 + 36
m<M = 51°
m<L = 180° - (m<M + m<K) (sum of triangle theorem)
Substitute
m<L = 180 - (51 + 51)
m<L = 78°