Question

Raquel is cutting out pieces of cardboard to make a pyramid. She will use a square piece for the base and identical triangular pieces for the sides. The figure above shows the dimensions of the triangle for each side. What will be the total surface area, in square inches, of the pyramid, including the square base?​

Answer 1

340 inch²

Explanation:

Side of the square is equal to the base of the triangle.

Area of square base

= side²

= (10 inch)²

= 100 inch²

Area of each triangle

= ½ × base × height

= ½ × 10 inch × 12 inch

= 10 inch × 6 inch

= 60 inch²

So, area of 4 triangles used

= Area of each triangle × 4

= 60 inch² × 4

= 240 inch²

Total surface area of pyramid

= Area of square base + area of 4 triangles

= 100 inch² + 240 inch²

= 340 inch²