Answer:
y = 9[tex]\sqrt{2}[/tex] inches
Step-by-step explanation:
Since the base angles are congruent then the triangle is isosceles with both legs being equal.
Using Pythagoras' identity in the right triangle
y² = 9² + 9² = 81 + 81 = 162 ( take the square root of both sides )
y = [tex]\sqrt{162}[/tex] = [tex]\sqrt{81(2)}[/tex] = 9[tex]\sqrt{2}[/tex]
