To find the area of the polygon, we need to break it down into smaller shapes. The polygon is made up of two rectangles (with dimensions 12 x 3 and 5 x 3) and two triangles.
Area of the first rectangle = 12 x 3 = 36 square units
Area of the second rectangle = 5 x 3 = 15 square units
To find the area of the triangles, we need to find their base and height. The base of each triangle is 3 units (the width of the vertical sides) and the height is h units.
Using the Pythagorean Theorem, we can find the height:
h^2 + 3^2 = 6^2
h^2 + 9 = 36
h^2 = 27
h ≈ 5.2 (rounded to 1 decimal place)
Now we can find the area of each triangle:
Area of first triangle = (1/2) x 3 x 5.2 ≈ 7.8 square units
Area of second triangle = (1/2) x 3 x 5.2 ≈ 7.8 square units
Finally, we can add up the areas of all the shapes to find the total area of the polygon:
36 + 15 + 7.8 + 7.8 = 66.6 square units
Therefore, the closest answer among the options provided is 68 square units.