A squared plus b squared equals c squared is the formula or equation that is used regarding pythagorean theorem. The two opposite sides are a and b in that picture. Since one side is 18 and it is equal to the other line(hence the dashes), the other line is 18. Let’s plug this into the equation:
(18^2) + (18^2) =c^2
324 +324 = c^2
648=c^2
Now you have to find the square root of 648. The square root of 648 is 18√2.
C is equal to 18√2.
