Question

Someone please help me with this problem?

Answer 1

Side BC is also side a. You can find it using the Law of Sines. Do you know the Law of Sines?

Answer 2

No I don't , can you help me?

Answer 3

@IMStuck

Answer 4

I sure can!

Answer 5

This is the Law of Sines.

Answer 6

\[\frac{ sinA }{ a }=\frac{ sinB }{ b }=\frac{ sinC }{ c }\]Two things here...the lowercase letters indicate side lengths and the uppercase indicate angles, and you only need 2 of the 3 ratios to solve for your missing side.

Answer 7

You know angle C and side c, and you can solve for angle A, right? What is angle A?

Answer 8

You need angle A because you are looking for side a.

Answer 9

im not sure what Angle A is

Answer 10

you find it like this. all the degrees of a triangle add up to 180 degrees, so
180-79-30=angle A. Angle A = 71

Answer 11

Now you have angle C of 30 and side c of 11, and you have angle A of 71, and you need side a. So this is your ratio using the Law of Sines:

Answer 12

\[\frac{ \sin(30) }{ 11 }=\frac{ \sin(71) }{ a }\]Cross multiply to find a, like this:

Answer 13

(a)sin(30)=(11)sin(71)

Answer 14

or
\[a=\frac{ (11)\sin(71) }{ \sin(30) }\]

Answer 15

sin(71)=.94551 and multiplied by 11 it is 10.4007 That is the numerator now. The denominator is the sin(30) which is .5 So 10.4007/.5 is the length of side a.

Answer 16

a=20.8

Answer 17

thank you!!!!

Answer 18

You really need to know this. Study up on it; it is indispensable when it comes to triangles!

Answer 19

You're welcome!