Answer:
C. 891.
Step-by-step explanation:
This is a regular nonagram ( has 9 sides) so the area is the sum of 9 congruent triangles.
Area of a triangle = 1/2 * base * height
Area of 1 triangle in this polygon = 1/2 * 12 * 16.5
Area of the polygon = 9 * 1/2 * 12 * 16.5
= 891
