How high must a 40 gallon tank be if the base is a square 3 feet 9 inches on a side

so if the base is a square, which is 3'9" on a side, that means the tank is just a tall square, namely a rectangular prism.

since there are 12 inches in 1 foot, then 3 feet is 36 inches, and 3'9" is then 36" + 9" or 45 inches, so the base is a 45"x45" square.

now, let's covert the gallons to inches as well, namely in³, keeping in mind a (US) gallon has 231 in³, then 40 gallons will be 40*231 or 9240 in³.

the answer to this question is in the pic

d) 30 units^2

area of rectangle = l × b

we know,

length = 10 unit

breadth = 3 unit

applying the formula,

= l × b

= 10 × 3

= 30 unit^2

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