Question

Use the Law of Sines. Find the indicated measure to the nearest tenth. In Triangle RST, m∠R =78, m∠T =39, and TS with line on top = 19 in. Find RS. a. 12.2 in c. 15.8 in b. 10.7 in d. 20.7 in

Answer 1

RS = 12.2 in ⇒ answer (a)

Explanation:

∵ m∠R = 78° , m∠T = 39° , TS = 19

∵ By using sin Rule:

∵ ST/sin∠R = RS/sin∠T

∴ 19/sin78 = RS/sin39

∴ RS = (19 × sin39) ÷ sin 78 = 12.2 in ⇒ answer (a)