What is the area, in square units, of trapezoid ABCD shown below?

Given:
Trapezoid with bases 10 and 20, and height of the trapezoid is 6.
To find:
The area of the trapezoid.
Solution:
We know that the area of a trapezoid is:
[tex]A=\dfrac{1}{2}h(b_1+b_2)[/tex]
Where, h is the height of the trapezoid and [tex]b_1,b_2[/tex] are bases of the trapezoid.
Putting [tex]h=6, b_1=10,b_2=20[/tex] in the above formula, we get
[tex]A=\dfrac{1}{2}(6)(10+20)[/tex]
[tex]A=3(30)[/tex]
[tex]A=90[/tex]
The area of the trapezoid is 90 sq units. Therefore, the correct option is A.