Answer:
Ron is because the 7 and the 2 are the inside box while 10 and 12 are the outside, hope this helps :)
Step-by-step explanation:
C. Use the formula for area of a triangle 1/2(Base * Height). Using that we see that we have 1/2(a*b) + 1/2(c*c) + 1/2(a*b). Cleaning this up we get 1/2(2ab+c^2)