374,636 views
27 votes
27 votes
Solve completely (all missing sides and all missing angles) using trig ratios or laws. Round to the nearest tenth.

Solve completely (all missing sides and all missing angles) using trig ratios or laws-example-1
User Alexandra Dudkina
by
2.7k points

1 Answer

20 votes
20 votes

Answer:

Explanation:

3. Use Cosine law to find the length of the unknown side (PR)

q² = p² + r² - 2prCos Q

q is the opposite side of ∠Q;

p is the opposite side of ∠P; p = 33

r is the opposite sides of ∠R ; r = 67

q² = 33² + 67² - 2* 33*67 Cos 19°

= 1089 + 4489 - 4422 * 0.95

= 1089 + 4489 - 4200.9

= 1377.1

q = √1377.1

q = 37.1

PR = 37.1

To find the angle use law of sin


\sf (q)/(Sin \ Q) =(p)/(Sin \ P)\\\\\\(37.1)/(Sin \ 19)=(33)/(Sin \ P) \\\\\\(37.1)/(0.33)=(33)/(Sin \ P)\\\\\\37.1* Sin \ P = 33 *0.33\\\\Sin \ P =(33*0.33)/(37.1)

Sin P = 0.3


P = Sin^(-1) 0.3\\

P = 17.5°

∠R = 180 - (19 + 17.5)

= 143.5°

User Ansona
by
2.6k points