Since it is a square you can use the Pythagorean theorem (a²+b²=c²) by filling in what you know. a²=5 and b²=5 so you have 5²+5²=c². This simplfies to 25+25=c². Now you simplify again to get 50=c². Finally you have to square root everything because the equation can't end in c², it has to be the most simplified it can be. This equals ≈7.1
Set up a proportion. 2/5 = x/40 to solve the equation first cross multiply. x*5=40*2 x*5=80 now divide both sides by 5, 80 divided by 5 is equal to 16. so the number of girls in the computer lab is 16.
