Answer:
c = 82 cm
Step-by-step explanation:
Using Pythagoras' identity in the right triangle.
The square on the hypotenuse is equal to the sum of the squares on the other 2 sides, that is
c² = 18² + 80² = 324 + 6400 = 6724 ( take the square root of both sides )
c = [tex]\sqrt{6724}[/tex] = 82
