Answer:
that's a right angled triangle , that's how it looks ..
so, you can apply Pythagoras theorem here, which states ;
(hypotenuse)² = ( perpendicular)² + ( base)²
[tex] {x}^{2} = {(36)}^{2} + {(77)}^{2} \\ = 1296 + 5929 \\ = 7225[/tex]
now ,
[tex] {85}^{2} = 7225[/tex]
so,
[tex] {x}^{2} = 7225 = {85}^{2} \\ therefore \: x = 85[/tex]
so, your answer is 85
