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  1. The volume of a pyramid with an isosceles triangular base is 240 square centimeters and it's height is 20 cm. The base of the base triangle is 6 cm. What is the length of the other two sides of the base?

  2. Jerry is packing cylindrical cans with diameter 6 in. and height 10 in. tighly into a box that measures 3 ft by 2 ft by 1 ft. All rows must contain the same number of cans. The cans can touch each other. He then fills all the empty space in the box with packing foam. How many cans can Jerry pack in one box? Find the volume of packing foam he uses. What percentage of the box's volume is filled by the foam?

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"The volume of a pyramid with an isosceles triangular base is 240 square centimeters". The unit of volume may be cubic centimeters, but not square centimeters. –  Américo Tavares May 15 '12 at 23:35
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1 Answer

Hint for the first question: Let the length of the other two sides of the isoceles triangle be $x$ cm. Thus, the isoceles triangle has side lengths 6 cm, $x$ cm, and $x$ cm. What is the area of this triangle in sq cm? (You will get an expression including an $x$.) Once you have computed that, apply the formula for the volume of a pyramid having height $h$ and base area $B$. You know that this quantity equals 240 cubic cm; now solve for $x$.

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