Question

the equation sin(40°) = b/20 can be used to determine the length of line segment ac. what is the length of ac? round to the nearest tenth. 11.8 cm 12.9 cm 14.9 cm 15.3 cm

Explanation:

Step1: Isolate the variable $b$.

Given $\sin(40^{\circ})=\frac{b}{20}$, multiply both sides by 20. So $b = 20\times\sin(40^{\circ})$.

Step2: Calculate the value of $b$.

We know that $\sin(40^{\circ})\approx0.6428$. Then $b = 20\times0.6428=12.856$.

Step3: Round the result.

Rounding $12.856$ to the nearest tenth gives $12.9$.

Answer:

$12.9$ cm