Question 46 Answer and Explanation _ACT June 2020 Form C02 Math Section

46. A surveyor needs to find the length from point A to point C across a lake as shown in the figure below. The measurements of which of the following angles and side lengths are sufficient for the surveyor to determine the length of AC using only the law of sines?

(Note: The law of sines says $\frac{a}{sin\,A}=\frac{b}{sin\,B}=\frac{c}{sin\,C}$ .)

F. angle:A,B ; side length:a

G. angle:A ; side length:c

H. angle:B ; side length: a, c

J. angle:B ; side length:c

K. angle:C ; side length:a

Answer and Explanation

Your Answer is

Correct Answer is F

Explanation

Because a/sinA=b/sinB=c/sinC, if b is required, you need to know the values of sinA, SinB and a (or the values of SinC, SinB and c), that is, A, B, a (or the values of C, B, and c), so choose A