Question

A triangular pyramid has a base shaped like an equilateral triangle. The legs of the equilateral triangle are all 4 feet long, and the height of the equilateral triangle is 3.5 feet. The pyramid's slant height is 3 feet. What is the surface area?

Answer 1

Answer:

Total surface area of the pyramid =    $25ft^{2}$

Step-by-step explanation:

To find the surface area of the triangular- based pyramid, we will use the formula:

Surface area = Area of base + Area of the three faces

Area of base of the pyramid = Area of equilateral triangle = $0.5 \times base \times height$

$= 0.5 \times 4 \times 3.5= 7ft ^{2}$

Area of the slant faces of the pyramid is $0.5 \times base \times slant height$

$0.5 \times 4 \times 3 = 6 ft^{2}$

Since there are 3 slant surfaces the total surface area of the pyramid =$7 + 3 \times (6)= 25ft^{2}$