18.44 because Pythagorean Theorem says that 12^2 + b^2 = 22^2. Then to solve you square the numbers, 144 - b^2 = 484, then subtract 144 from 484 and get 340, and the square root of 340 is 18.44.
20% is .20/ 20/50 is 40% or .4 or 4/10/ 9% is .09 or 9/100 / 9/10 is 90% or .9/ 66% is .66 or 33/50 or 66/100/ 6/10 is 60% or 60/100 or .6/ 2% is .02 or 1/50 or 2/100. I didn't exactly understand the question, but I hope this answers your question.
This question you can use simple elimination, can save you time if it's right. Obviously its not A or B as the hypotenous needs to be bigger than the base. Knowing the base is 32, there is not enough room to justify an additional 20 feet, eliminating D. Answer must be C. If you wanted to do it the right way use trig/socatoa to find the missing hypotenouse as the top angle of the triangle is 45, just like the other upside down one.