The value of x and y are 67°
Since the dotted line is a bisector of the apex angle in the triangle therefore the triangle is isosceles and x and y are equal.
A triangle is a 3 sided polygon. An isosceles triangle is a triangle with two equal length and equal corresponding angles.
The sum of angles in a triangle is 180°.
To find y
90 + 23 + y = 180 ( sum of angle in a triangle)
113 + y = 180
y = 180 - 113
y = 67°
Since y = x
we can therefore say that
x = 67°
Therefore, the value of x and y is 67°