math
posted by tee .
the international space station orbits 350 km above earth's surface. earth's radius is about 6370 km.use the pythagorean theorem to find the distance from the space station to earth's horizon.

sqrt[(6370+350)^2 (6370)^2]
= 2140 km
The hypotenuse is 6720 and the radius (6370) from the center to the point of tangency is perpendicular to the earth's surface 
let that distance be x
solve ...
x^2 + 6370^2 = 6720^2
( I got 2140.44) 
Yeah so add 20 plus 11 and get 47 , that's the short way , because once you do that , you'll easily get 2140.5 , you welcome.

an equilateral triangle has a perimeter of 120 inches what is the area of the triangle answer in radical form