Tommy and Erin are building a skateboard ramp. They want the ramp to be 3 feet tall and 5 feet long. Tommy thinks that they can use a piece of plywood that is 4 feet long to cover the top of the frame.

Full question is attached.

Tommy's reasoning is wrong because the hypotenuse is not 5 feet.

A skateboard ramp resembles a right angles triangle so its sides resemble that of a right angled triangle.

The height of 3 feet would be the height of the triangle.

The length of 5 feet would be the length of the triangle.

The piece of plywood that would cover the top of the frame would be the hypotenuse.

In using the Pythagoras rule, the c is the hypotenuse but Tommy made the mistake of assuming that the hypotenuse was b which is where the error came from.

Instead of solving for b, they should have been solving for c which is the hypotenuse.

a² + b² = c²

3² + 5² = c²

9 + 25 = c²

c² = 34

c = √34

c = 5.83 feet

They should use a plywood of 5.83 feet not 4 feet.