you want to find the area of the whole square first and then calculate the area of the of the white triangle. (Area= length x width) area= 18x18 area of whole square= 324 now you want to find the area of the white triangle you know the base of that triangle is 18 m because the square is the same length on all of the sides. area of triangle= b x h/2 area of triangle = 18x9/2 area of triangle= 162/2 area of triangle = 81 now subtract the area of the whole square and the area of the triangle area of blue part= 324-81 area of blue part= 243 and area of white part (which is the triangle) =81
