Question

Find the value of x ​

Answer 1

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
`-66` 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`