Learn about the surface area and volume of prisms with this BBC Bitesize Maths article. ... {12×5}{2}\) = 30 cm².The area of the rectangular faces are10 × 5 = 50 cm², ...

The area of the trapezium-shaped cross-section is given, 20 mm². The surface area of the prism is made up of two trapezium-shaped faces and four rectangular faces.