Step-by-step explanation:
4)
the surface area is
top and bottom : 2× pentagon (5 sides)
sides : 5× rectangle 14×8 ft²
let's start with the easiest : the rectangles.
5 × 14×8 = 560 ft²
the area of a pentagon is similar to any regular polygon :
n × triangle of side×height (to middle of pentagon) / 2
n = number of sides (5 in our case).
the middle or center of the pentagon is the top vertex of each triangle.
so,
5 × 14×9.63 / 2 = 5 × 7 × 9.63 = 337.05 ft²
and we have 2 of them (top and bottom), so
2×337.05 = 674.1 ft³
in total the surface area is
560 + 674.1 = 1,234.1 ft²
5)
6 sides :
top and bottom : 7×14 rectangle
left and right : 7×8 rectangle
front and back : 8×14 rectangle
so, we have
2× 7×14 = 196 mm²
2× 7×8 = 112 mm²
2× 8×14 = 224 mm²
in total that is : 532 mm²
