Find the value of x

Question

asked Jul 18, 2021 195k views

1 Answer

Salim Lachdhaf · Answer 1 · 2021-07-24T17:21:04+0000

Answer:

x° = 123

Explanation:

this triangle is isoceles so it has 2 congruent angles.

let y be the second angle

the sum of a triangle's angle is 180°

$180 = 66 + y + y \\180 = 66 + 2y$

add
to both sides

$180 - 66 = 2y + 66 - 66 \\114 = 2y$

divide both sides by 2

(114)/(2) = (2y)/(2)

57 = y

we khow that
x + y = 180

$x + y = 180 \\x + 57 = 180$

add -57 to both sides

$x + 57 - 57 = 180 - 57 \\x = 123$