Set up a proportion
42.50/5=x/8
5x=340
x=68
He would earn $68
No the side lengths of 9,12, and 18 doesn’t form a right triangle. Posted a picture showing all the side length that is a right triangle.
Answer: If you are reflecting the triangle(or coordinate points in general) off of the x or y axis on the upper quadrants, then the reflection would be negative for x.
If you are reflecting the triangle(or coordinate points in general) off of the x or y axis on the lower quadrants, then the reflection would be negative for y.
This is because the lower quadrants are usually negative and the upper quadrants are usually positive according to the x axis. The same thing vice verse with y.
These are the rules that I’m guessing your trying to find. Hope this helps!