Question

PLEASE HELP: MEDAL AND FAN

Solve the triangle.

A = 51°, b = 11, c = 7

Answer 1

@campbell_st

Answer 2

can you help? @swamijatin2

Answer 3

what we have to find perimeter or area

Answer 4

neither

Answer 5

lol wrong thing sorry

Answer 6

I need a (side a); C(angle c); and B(angle b)

Answer 7

@campbell_st

Answer 8

ok

Answer 9

or well that doesnt have to be a right triangle but

Answer 10

now what

Answer 11

@satellite73

Answer 12

how do i do this

Answer 13

draw a triangle that looks reasonably like this one
then use the law of cosines

Answer 14

i have a triangle but how do i use the law of cosines (i know what it is just not how to do it)

Answer 15

\[a^2=b^2+c^2-2bc\cos(A)\]
\[a^2=11^2+7^2-2\times 11\times 7\cos(51^\circ)\] and a calculator

Answer 16

To solve the traingle we need to find remaining side a and angles B and C.
Use law of cosines
a2 = b2 + c2 - 2bc cosA
a2 = (11)2 + (7)2 - 2(11)(7) cos(51)
a2 = 121 + 49 - 154 cos(51)
a2 = 170 - 154(0.629)
a2 = 170 - 96.866
a2 = 73.134
a = 8.55

Answer 17

i got that ok so how about the and C

Answer 18

B and C angles

Answer 19

Now use law of sines sinA/a = sinB/b
sin(51)/ 8.55 = sin(B)/11
sin(B) = 11[sin(51)/ 8.55]
sin(B) = 11[0.777/8.55]
B = sin-1(0.999)
B = 87.43°

Answer 20

ok and C?

Answer 21

Sum of angles in triangle = 180°
A + B + C = 180
C = 180 - (A + B)
C = 180 - (51 + 87.43)
C = 180 - 138.43
C = 41.57°

Answer 22

http://www.wolframalpha.com/input/?i=sqrt%2811^2%2B7^2-2*11*7*cos%2851%29%29

Answer 23

because none of those are my answers

Answer 24

then you are incorrect anywhere

Answer 25

what?

Answer 26

did u get the answers

Answer 27

8.5 is a which is only for one answer choice where B = 85.9 and C = 39.1

Answer 28

a ≈ 12.8, C ≈ 39.1, B ≈ 89.9
a ≈ 8.5, C ≈ 39.1, B ≈ 89.9
No triangles possible
a ≈ 12.8, C ≈ 43.1, B ≈ 85.9

Answer 29

you r correct but according to question we have to do

Answer 30

@Loser66

Answer 31

please finish helping me @swamijatin2

Answer 32

@phi

Answer 33

we have done a lot but it doesn't match my answer choices

Answer 34

can you re-post the question and the answer you got? It would take a long time to read through all of the posts up above.

Answer 35

sure hold on

Answer 36

Solve the triangle.

A = 51°, b = 11, c = 7

Answer 37

Work From above:
a2 = b2 + c2 - 2bc cosA
a2 = (11)2 + (7)2 - 2(11)(7) cos(51)
a2 = 121 + 49 - 154 cos(51)
a2 = 170 - 154(0.629)
a2 = 170 - 96.866
a2 = 73.134
a = 8.55
Now use law of sines sinA/a = sinB/b
sin(51)/ 8.55 = sin(B)/11
sin(B) = 11[sin(51)/ 8.55]
sin(B) = 11[0.777/8.55]
B = sin-1(0.999)
B = 87.43°
Sum of angles in triangle = 180°
A + B + C = 180
C = 180 - (A + B)
C = 180 - (51 + 87.43)
C = 180 - 138.43
C = 41.57°

Answer 38

My answer choices are:
a ≈ 12.8, C ≈ 39.1, B ≈ 89.9
a ≈ 8.5, C ≈ 39.1, B ≈ 89.9
No triangles possible
a ≈ 12.8, C ≈ 43.1, B ≈ 85.9

Answer 39

so... what do we do?

Answer 40

side a is correct. a= 8.55

redo your work for angle B

Answer 41

the problem is when you do the work for angle B, you need lots of decimals of accuracy.
for side a, don't round it to 8.55. use all the digits your calculator has.

Answer 42

ok

Answer 43

it might be more accurate to first find angle C
sin C = (7*sin51)/8.548956649

Answer 44

what do you get for angle B i got the same answer

Answer 45

I got 0.63633750 Radians for C?

Answer 46

sin C = 0.63633750
C= asin( 0.63633750 ) = 39.519 deg

Answer 47

summarizing
a= 8.55, b= 11, c= 7
A= 51, B= 89.5, C= 39.5

the best match to your choices is choice B

Answer 48

if we use a=8.6 (round from 8.55) we would get
C= 39.2 and B= 89.8
which is even closer to choice B.

Answer 49

because they use ≈ which means approximately
it is reasonable to pick choice B. And the other choices are not "in the ball park"