Solution to Stinger #65 
by Steve Rosin

Suppose a pyramid with a square base has a height of 30 feet. The slanted 
sides are four identical isosceles triangles each of which has area 600 square feet. 
Find the exact length of the base sides.

Let the  base=2x.  Then (30)(30)+(x)(x)=(h)(h), or 900+x2=h2, or x2=h2-900.



(1/2)(2x)(h)=600, so xh=600, or x=(600/h), or x2=(360000/h2)

(360000/h2)=h2-900
360000=h4-900h2
h4-900h2-360000=0
h2+300=0
h2-1200=0
h2=1200

x2=1200-900
x2=300
x=(300)^(1/2)
base=2(300)^(1/2)

Math Stinger #65