The surface area of the prisms are
1. 340m²
2. 60.45cm²
3. 80in²
The surface area of a prism is calculated as;
SA = 2B + ph
where B is the base area and p is the perimeter of the base and h is the height.
1. Area of base = 1/2 × 12 × 5
= 30m²
perimeter = 7 + 9 + 12 = 28m²
height = 10m
SA = 2× 30 + 28 × 10
= 60 + 280
= 340m²
2. base area = 1/2 × 2.6 × 3.9
= 5.07
perimeter = 5.2 + 2.6 + 3.9
= 11.7
height = 4.3
SA = 2 × 5.07 + 4.3 × 11.7
= 10.14 + 50.31
= 60.45cm²
3. base area = 1/2× 4 × 3.5
= 7in²
perimeter = 4 + 4 + 4 = 12in
height = 5.5
SA = 2 × 7 + 12 × 5.5
= 14 + 66
= 80in²