What the value of x and y are?

A triangle add up to 180. So, 55°+90°+___=180°
The answer is: y= 35°

The side with 13 equals to 2x+1 
2x+1=13
2x=13-1
2x=12
The answer is: x=6

Hope this answer helps!

Since the mid line is the perpendicular bisector:

Hence angle on the right is also y.

y + 55 + 90 = 180       sum of angles in a triangle.

y + 145 = 180

y = 180 - 145

y = 35

y = 35°

We can go ahead to show that the two angles are congruent   ASA

Therefore:

2x + 1 = 13

2x = 13 - 1

2x = 12

x = 12/2

x = 6

x = 6 and   y = 35°

Hope this explains it.