Answer:
The area of the pentagon is: 354
Explanation:
First draw two auxillery lines in the upper left hand corner to make a rectangle, and a right triangle.
Now that we have a rectangle we can find its area:
18·20=360
To find the lengths of the triangle sides:
20-16=4
18-15=3
Area of a right triangle formula: (leg a · leg b)/2
3·4=12 12/2=6
Now subtract the area of the triangle from the rectangle:
360-6=354