ok heres the info.
PCDEF is a regular square pyramid w/ altitude (line segment) PH and a slant height (line segment) pj. If PH is 21 and the area of the base is 1600 whats (line segment) PJ
2007-04-30 16:51:27 · 3 answers · asked by its me 1 in Science & Mathematics ➔ Mathematics
the base of a square pyramid, is just a square, so:
A=length^2 = 1600
so the length of one side of the base is 40.
since you know the base, and the height, this forms a right triangle with the slant height (with slant height being the hypoteneuse).
for a right triangle, use the pythagorean thm:
(21)^2 + (40)^2 = pj^2
2041 = pj^2
pj = 45.1774
2007-04-30 16:57:52 · answer #1 · answered by horrid 3 · 0⤊ 0⤋
This requires a bit of 3-d visualization.
First, the base of the pyramid is 40. If you draw a triangle with the altitude as one side, a line from the midpoint of one of the bases to the altitude as a second side, and PJ as a third. You will have a right triangle with 2 sides of 21 and 20 and PJ as the hypotenuse. PJ = 29= sqrt(441+400)
2007-05-01 00:06:47 · answer #2 · answered by cattbarf 7 · 0⤊ 0⤋
Square root of 2041.
2007-04-30 23:59:45 · answer #3 · answered by hookemhornsfan1991 2 · 0⤊ 0⤋