An eight-sided game piece is shaped like two identical square pyramids attached at their bases. The perimeters of the square bases are 80 millimeters, and the slant height of each pyramid is 17 millimeters. What is the length of the game piece?
+129852 If the perimeter of a square base = 80 mm, then the side of one of these squares = 20mm
The length of the diagonal of the square = √2 * side length = √2 * 20 = 20√2 mm
And (1/2) of this length is the leg of a right triangle with the slant height the hypotenuse = 10√2 = √200 mm
Using the Pythagorean Theorem...(1/2) the height of this game piece =
√ [slant height^2 - (1/2 diagonal length)^2] =
√[17^2 - (√200)^2 ] = √[289 - 200 ] = √89 mm
So....the height of the game piece is twice this = 2√89 mm ≈ 18.87 mm
+1490 An eight-sided game piece is shaped like two identical square pyramids attached at their bases. The perimeters of the square bases are 80 millimeters, and the slant height of each pyramid is 17 millimeters. What is the length of the game piece?
Square side is a = 80/4 = 20 mm a/2 = 10 mm
Slant height is S = 17 mm
Pyramid height h = sqrt [S2 - ( a/2 )2] h = 13.74772708 mm
The length of the game piece is L = 2h = 27.49545417 mm 
