Start by proving to them that the number 0.57 can be converted into a fraction . A whole number can't exactly be put in to a fraction. 0.57 can be converted to 14.25/25. This information means that 0.57 IS a rational number. Hope this convinced them!
You need a picture to lable and draw it so we can awnser your question
Angle C and the 112 degree angle are supplementary, so angle C measures 180-112=68 degrees.
This means that by the exterior angle theorem, 
36 inches=2 feet
72 inches= 4 feet