The trapezoid shown in the given figure represents a cross section of the rudder of a ship.If the distance from A to B is 13 feet, what is the area of the cross section of the rudder in square feet?
The formula for calculating the area of a trapezoid is
$Area=\dfrac{1}{2}\left(base1+base2\right)\left(height\right)$
The bases of the trapezoid are given as 2 feet and 5 feet, so only the height (AQ) needs to be found.
Since the dashed line AB=13 feet, and triangle BQA is a right triangle, use the Pythagorean theorem to calculate AQ.Thus,
AQ=$\sqrt{13^{2}-5^{2}}$
=$\sqrt{144}$
=12
Substituting the values into the formula for calculatingthe area of a trapezoid:
$Area=\dfrac{1}{2}\left(2+5\right)\left(12\right)$
=42 square feet