Is it asking for perimeter or area?
Perimeter is equal to side+side+side+side. To get the whole number of 8 1/2, turn it into a whole number by multiplying 8 by 2 and adding 1. You'll get 17/2. Divide and you'll get 8.5.
If it's asking for area just add 8.5+15+23+10 and you'll get your answer.
Area is equal to (15+23) and divide it by 2. Next multiply it by 8.5