document.write( "Question 1065772: A triangular pyramid has a lateral surface of 225 square centimeters. If the height of the pyramid is greater than 12 centimeters and the base has nine equal sides, what are whole-number possibilities for the height and width of each triangular face? \n" ); document.write( "
Algebra.Com's Answer #680938 by Theo(13342)\"\" \"About 
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lateral surface area doesn't include the area of the base.
\n" ); document.write( "if there are 9 equal sides, then there are 9 equal triangles.
\n" ); document.write( "that means the area of each triangle is 25 square centimeters.
\n" ); document.write( "the formula for the area of a triangle is 1/2 * b * h.
\n" ); document.write( "you get 1/2 * b * h = 25
\n" ); document.write( "multiply both sides of this equation by 2 and you get b * h = 50
\n" ); document.write( "divide both sides of this equation by h and you get b = 50 / h
\n" ); document.write( "since b > 12, then 50 / h > 12.
\n" ); document.write( "multiply both sides of this equation by h to get 50 > 12 * h.
\n" ); document.write( "looks like h is a multiple of 12 and can be 1, 2, 3, or 4.
\n" ); document.write( "it can't be 5 because 12 * 5 = 60 > 50.
\n" ); document.write( "to test these out, use the formula of 25 = 1/2 * b * h and multiply both sides of it by 2 to get 50 = b * h.
\n" ); document.write( "if b = 1, then h = 50 > 12 which is a whole number.
\n" ); document.write( "if b = 2, then h = 25 > 12 which is a whole number.
\n" ); document.write( "if b = 3, then h = 15 and 5/15 > 12 but is not a whole number.
\n" ); document.write( "if b = 4, then h = 12 and 2/12 > 12 but is not a whole number.
\n" ); document.write( "if b = 5, then h = 10 which is smaller than 12.
\n" ); document.write( "my guess is that the base can either be 1 or 2.
\n" ); document.write( "when 1, the height is 50.
\n" ); document.write( "when 2, the height is 25.
\n" ); document.write( "the area of each triangle is always 25.
\n" ); document.write( "the lateral area is always 225.\r
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