85(2)= 170
15(4)(3)= 180
3.2(45)(8)= 1152
-16/4 = -4 degrees F....answer C
Answer:
see explanation
Step-by-step explanation:
Using the Sine rule in all 3 questions
(1)
=
, substitute values , firstly calculating ∠ B
[ ∠ B = 180° - (78 + 49)° = 180° - 127° = 53° ]
=
( cross- multiply )
a sin53° = 18 sin78° ( divide both sides by sin53° )
a =
≈ 22.0 ( to the nearest tenth )
(3)
=
, substitute values
=
( cross- multiply )
45 sinC = 35 sin134° ( divide both sides by 35 )
sinC =
, then
∠ C =
(
) ≈ 34.0° ( to the nearest tenth )
(5)
Calculate the measure of ∠ B
∠ B = 180° - (38 + 92)° = 180° - 130° = 50°
=
, substitute values
=
( cross- multiply )
BC sin50° = 10 sin38° ( divide both sides by sin50° )
BC =
≈ 8.0 ( to the nearest tenth )
1. 0.3% or 30%
2. 15 minutes
3. 48 times