Answer:
area of polygon = 88 sq. units
Step-by-step explanation:
lets make it simple, short and accurate.
area of polygon = total area - total area of triangles
total area = 11 * 12 = 132
triangle 1 = 1/2 * 5 * 5 = 12.5
triangle 2 = 1/2 * 3 * 6 = 9
triangle 3 = 1/2 * 3 * 8 = 12
triangle 4 = 1/2 * 3 * 7 = 10.5
total area of triangle = 12.5 + 9 + 12 + 10.5 = 44
area of polygon = 132 - 44 = 88 sq. units