Question

9 can someone please explain this

Answer 1

D

Explanation:

The vertex of the triangle is adjacent to 90° on a straight line, so

vertex = 180° - 90° = 90°

The triangle has 2 congruent sides and is therefore isosceles with 2 congruent base angles, then

x =
`(180-90)/(2)` =
`(90)/(2)` = 45° → D