Answer:
21
Step-by-step explanation:
we know that according to the isosceles triangle theorem, that the angles of the triangle are 90, 2x+3, 2x+3
from the triangle angle sum theorem, we know that 4x+6 = 90
solving, we get 4x=84, x=21
isosceles + a right angle, so both angles at the bottom are the same and equal to (2x+3).
so we have 180 degrees = 90 + (2x+3) + (2x+3)
so x = 21
