Hello! First, we must remember some concepts:
the sum of the three internal angles of a triangle equals 180º.
a right triangle has an angle equal to 90º.
Knowing that, let's solve this exercise:
We know the measurement of two angles:
Remembering that the sum of all angles must be 180º, let's calculate:
23º23' + 90º + x = 180º
113º23' + x = 180º
x = 180º - 113º23'
x = 66°37
So, x = 66º37'.