Given:
The figure of a polygon.
To find:
The area of the polygon.
Solution:
Area of a triangle is
[tex]Area=\dfrac{1}{2}\times Base\times Height[/tex]
Area of trapezoid is
[tex]Area=\dfrac{1}{2}(a+b)h[/tex]
Where, a, b are bases and h is the height.
The area of the triangle with base 6 cm and height 8 cm is
[tex]A_1=\dfrac{1}{2}\times 6\times 8[/tex]
[tex]A_1=24[/tex]
Height of the trapezoid is [tex]13-8=5\ \text{cm}[/tex] and the bases are 6 cm, 12 cm. So, the area of the trapezoid is
[tex]A_2=\dfrac{1}{2}(6+12)(5)[/tex]
[tex]A_2=\dfrac{1}{2}(18)(5)[/tex]
[tex]A_2=(9)(5)[/tex]
[tex]A_2=45[/tex]
Now, the total area of the polygon is
[tex]A=A_1+A_2[/tex]
[tex]A=24+45[/tex]
[tex]A=69[/tex]
Therefore, the area of the polygon is 69 sq. cm.