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CAN SOMEONE PLS HELP?? IM AB TO FAIL GEOMETRY AND NEED HELP W LAW OF SINES. PLEASE

1. In ΔABC, c = 5.4, a = 3.3, and . What are the possible approximate lengths of b? Use the law of sines to find the answer.
2.0 units and 4.6 units
2.1 units and 8.7 units
2.3 units and 7.8 units
2.6 units and 6.6 units
2)What is the approximate value of k? Use the law of sines to find the answer.
2.9 units
3.8 units
5.1 units
6.2 units

please help!!

CAN SOMEONE PLS HELP?? IM AB TO FAIL GEOMETRY AND NEED HELP W LAW OF SINES. PLEASE-example-1
CAN SOMEONE PLS HELP?? IM AB TO FAIL GEOMETRY AND NEED HELP W LAW OF SINES. PLEASE-example-1
CAN SOMEONE PLS HELP?? IM AB TO FAIL GEOMETRY AND NEED HELP W LAW OF SINES. PLEASE-example-2
User Darleen
by
8.2k points

2 Answers

6 votes

Part a) In ΔABC, c = 5.4, a = 3.3, and m∠A=20° . What are the possible approximate lengths of b? Use the law of sines to find the answer.

we know that


(sin\ A)/(a) =(sin\ B)/(b) =(sin\ C)/(c)

Step
1

Find the value of angle C


(sin\ A)/(a) =(sin\ C)/(c)


(sin\ 20)/(3.3) =(sin\ C)/(5.4)\\ \\ sin\ C=(5.4*sin\ 20)/(3.3) \\ \\ sin\ C=0.5597\\ \\ C=arcsin(0.5597)\\ \\ C=34\ degrees

Step
2

Find the value of angle B

we know that


A+B+C=180\\ B=180-(A+C)\\ B=180-(20+34)\\ B=126\ degrees

Step
3

Find the value of side b


(sin\ A)/(a) =(sin\ B)/(b)


(sin\ 20)/(3.3) =(sin\ 126)/(b)\\ \\ b=(3.3*sin\ 126)/(sin\ 20) \\ \\ b=7.8\ units

Step
4

Find the alternative angle C


C=180-34\\ C=146\ degrees

Find the alternative angle B


A+B+C=180\\ B=180-(A+C)\\ B=180-(20+146)\\ B=14\ degrees

Find the alternative value of side b


(sin\ A)/(a) =(sin\ B)/(b)


(sin\ 20)/(3.3) =(sin\ 14)/(b)\\ \\ b=(3.3*sin\ 14)/(sin\ 20) \\ \\ b=2.3\ units

therefore

the answer Part a) is the option


C:\ 2.3\ units\ and\ 7.8\ units

Part b) What is the approximate value of k? Use the law of sines to find the answer

Step
1

Find the value of angle J

we know that


J+K+L=180\\ J=180-(K+L)\\ J=180-(120+40)\\ J=20\ degrees

Step
2

Find the value of side k


(sin\ K)/(k) =(sin\ J)/(j)


(sin\ 120)/(k) =(sin\ 20)/(2)\\ \\ k=(2*sin\ 120)/(sin\ 20) \\ \\ k=5.1\ units

therefore

the answer Part b)


k=5.1\ units

User Svassr
by
8.1k points
3 votes
The laws of sines is already indicated in the provided images.

1. sin20/3.3 = sinC/5.4
Thus, angle C is 34.03 degrees. To find angle B: 180 - 20 - 34.03 = 126 degrees. Using the law of sines,

sin20/3.3 = sin(126)/b
b = 7.8 units

From this answer, we can already tell that the answer is letter C: 3 units and 7.8 units.

2. Angle J = 180 - 120 - 40 = 20 degrees. Then,

sin(20)/2 = sin(120)/k
k = 5.1 units
User Venryx
by
7.7k points