Can some one please help me figure out whats wrong with this graph

I think difference between values on y-axis should be same. For eg: 100,200,300,400,500

b) 76 square centimeters

step-by-step explanation:

divide the object into a square and rectangle. i drew a line down to get a rectangle with dimensions 4x10 and a square whose dimensions are 6x6. the area of the rectangle is 40 while the square is 36. to find the total add those together to get 76.