Every length in a 45°-45°-90° triangle increases by 20%. By what percent does the area of the triangle increase?	Choose the correct choice from the following answers.
A) 20% B) 25% C) 40% D) 44% E) 80%
The irony of this question is, of course, the specifics of the shape don’t matter at all. Yes, in general it is a good idea to be familiar with the 45°-45°-90° triangle —- if you’re not, see this post —– but none of that matters here.   We have a 20% increase, so that’s a multiplier of 1.2, which means k = 1.2. The multiplier for area would be k^2 = (1.2)^2 = 1.44, which is the multiplier for a 44% increase. That’s the percent increase in area. Answer = 44%
<result>D</result>
Every length in a 45°-45°-90° triangle increases by 20%. By what percent does the area of the triangle increase?