Answer:
Below in bold.
Step-by-step explanation:
If we draw a line from top right vertex perpendicular to the bottom line we get a right triangle.
Height of this triangle = sqrt(5^2 - 3^2) = 4.
This is also the height of the polygon.
The polygon is a trapezium so:
Area of the polygon = 1/2(5 + 8) * 4
= 6/5 * 4
= 26 m^2.
