Hello from MrBillDoesMath!
Answer:
The measure of x is 45 degrees in all triangles.
As each triangle has two equal legs (shown by the tick marks) the base angles opposite those legs are equal. But a triangle has 180 degrees 2x + 90 = 180, or 2x = 180-90 =90, so x = 45. All three triangles are 45-90-45 triangles.
Thank you,
MrB