In $\triangle{ABC}$ shown below, the given side lengths are in meters. Which of the following expressions gives the area, in square meters, of $\triangle{ABC}$.

Summary Submit Skip Question

If you draw an altitude from the base $\overline{AC}$ up to point $B$, we can make a right triangle. This triangle has a hypotenuse of 11, so we can use trigonometry to get the height of the triangle:

$$\sin{30^\circ} = \frac{\text{height}}{11}$$ $$\text{height} = 11\sin{30^\circ}$$

Using the area formula for the original triangle

$$A= \frac{1}{2}bh$$ $$A = \frac{1}{2}(10)(11\sin{30^\circ})$$ $$A = \boxed{\frac{1}{2}(11)(10)(\sin{30^\circ})}$$