The diagram is a net right rectangular pyramid ... - WAEC Mathematics 2010 Question

Total surface area = sum of the area of the (\bigtriangleup) S + Area of the rectangle

= 2 x Area of (\bigtriangleup) PTQ + 2 x Area of (\bigtriangleup) QUR + Area of rectangle PQRS

2 x (\frac{1}{2})(8 x 4) + 2 x (\frac{1}{2})(5 x 4) + 8 x 5

= 32 + 20 + 40

= 92cm²