Question

Triangle ABC is an Isosceles triangle, AB = AC, find the measure of x.

Answer 1

Answer:

Triangle ABC is isosceles

⇒ AB=AC

⇒ ∠ABC = ∠ACB

Find ∠ABC :

Since ΔABC is isosceles

∠ABC = (180 - 30 ) ÷ 2 = 75º

Find x:

∠ABC and x are on a straight line

⇒ both angles add up to 180º

x = 180 - ∠ABC

x = 180 - 75 = 105º

Find y:

∠ACB = ∠ABC = 75º

∠ACB and y are on a straight line

⇒ both angles add up to 180º

y = 180 - ∠ACB

y = 180 - 75 = 105º

Answer: x = y = 105º