The lengths of the sides of the triangle are 13 cm, 13 cm and 10 cm. The perpendicular height of the triangle is 12 cm.
The length of the prism is 8 cm.

Work out the total surface area of the prism.

20.62 feet

Step-by-step explanation:

The ladder propped against a building forms a right angle triangle

Height of the ladder (hypotenuse) = 21 feet

Base of the ladder from the building (adjacent) = 4 feet

Height of the building (opposite) = x feet

Hypotenuse ² = opposite ² + adjacent ²

21² = x² + 4²

21² - 4² = x²

441 - 16 = x²

425 = x²

x = √425

= 20.62 feet