I believe the answer is the fourth option.
Answer:
10
β
Step-by-step explanation:
We can find this two ways, first by seeing in the step after it, cosines are canceled out. Since you already have 10
β
on the next step, you can assume that (since only the cosines changed and the cosine next ot the blank was removed), the value is 10
β
.
You can also use double angle formulas from the previous step:
(sin(2β) = 2 sin(β) cos(β))and find that:
5 sin (2β) sin(β) = 5 * (2 sin(β) cos(β)) sin(β)) = (10 sin(β) sin(β)) cos(β) =
10
β
cos(β)
But since cos(β) is already present, we can see that the answer is 10
β
Answer:
Step-by-step explanation:
The sum of angle measures is ...
(7x +13)° +(83 -2x)° = 141°
5x +96 = 141 . . . . . collect terms, divide by °
5x = 45 . . . . . . . . . subtract 96
x = 9 . . . . . . . . . . . divide by 5
7x +13 = 7·9 +13 = 76 . . . . . find m∠J
m∠J = 76°
m∠K = 141° -76°
m∠K = 65°