Find the surface are of the fish tank if the base is a regular octagon with side length 0.9 units and the height of the prism is 2 units

19.11 square units

Step-by-step explanation:

The fish tank is composed by eight rectangles with base = 0.9 units and height = 2 units; and by a regular octagon at the bottom, which sides are 0.9 units long.

Area of each rectangle = 0.9*2 = 1.9 square units

Area of the regular octagon = 2*(1 + √2)*0.9² = 3.91 square units

Therefore:

Surface area of the fish tank = 8*1.9 + 3.91 = 19.11 square units

the answer is b.

step-by-step explanation:

-60.75

step-by-step explanation:

just add the numbers then put the negative sign on it