The surface area of a pyramid is equal to the sum of the areas of each side of the pyramid. The base of the pyramid has area , and and represent the slant height on the length and slant height on the width.

Substitute the values of the length , the width , and the height into the formula for surface area of a pyramid.

Multiply by .

Apply the product rule to .

Raise to the power of .

Raise to the power of .

Raise to the power of .

To write as a fraction with a common denominator, multiply by .

Combine and .

Combine the numerators over the common denominator.

Simplify the numerator.

Multiply by .

Add and .

Rewrite as .

Simplify the numerator.

Rewrite as .

Factor out of .

Rewrite as .

Pull terms out from under the radical.

Simplify the denominator.

Rewrite as .

Pull terms out from under the radical, assuming positive real numbers.

Cancel the common factor of .

Factor out of .

Cancel the common factor.

Rewrite the expression.

Multiply by .

Divide by .

Raise to the power of .

Raise to the power of .

Add and .

Rewrite as .

Factor out of .

Rewrite as .

Pull terms out from under the radical.

Multiply by .

Calculate the approximate solution to decimal places.

Find the Surface Area pyramid (20)(20)(15)