Answer:
[tex]\sqrt{73}[/tex]
Step-by-step explanation:
By the Pythagorean theorem, [tex]a^2 = b^2 + c^2[/tex] Where a is the hypotenuse (the longest side).
The hypotenuse of the triangle in the picture is c, which is what we are trying to work out:
[tex]c^2 =3^2+8^2=9+64=73\\\boxed{c=\sqrt{73}}[/tex]
