Question

Help please

Answer 1

I will help

Answer 2

with??

Answer 3

length of A is 20

Answer 4

How'd you get that?

Answer 5

use mathway.com

Answer 6

what's the exercise meant to cover anyway?

Answer 7

I used the The Pythagorean Theorem

Answer 8

use law of cosines

Answer 9

It's a review of this unit. The whole thing is over triangles.

Answer 10

lenght of A supposed to be the opposite side length of angle A

Answer 11

of "this unit"?

Answer 12

It's the current unit that my class is learning about. Vectors, triangles, etc.

Answer 13

law of cosine that is

Answer 14

it is related to vectors

Answer 15

well.. as xapproachesinfinity said, I can see the law of cosines there, for one

so... assuming you've covered it, if not, you may want to peruse it some first

Answer 16

So the formula I would use is c=sqrt a^2+b^2-2ac cos(theta), right?

Answer 17

\(\bf \textit{Law of Cosines}\\ \quad \\
a^2 = {\color{blue}{ c}}^2+{\color{red}{ b}}^2-(2{\color{blue}{ c}}{\color{red}{ b}})cos(A)\implies
a = \sqrt{{\color{blue}{ c}}^2+{\color{red}{ b}}^2-(2{\color{blue}{ c}}{\color{red}{ b}})cos(A)}\)

Answer 18

Okay, I'm working it out now

Answer 19

I got 387.817. Am I supposed to do the left side of the equation or are they the same?

Answer 20

nope, the left side is just the side "a"

now.... if c = 11 and b = 13 and a = 387

let us think on that one

if "c" and "b" stretch as long as they could, say like a flat line
the longest they could muster is 11 + 13

so.... that is all "a" can aspire to though... so 387... is kinda off the range

Answer 21

So all I had to do was add side b and c or my answer is supposed to be close to 24?

Answer 22

\(\bf a = \sqrt{{\color{blue}{ 11}}^2+{\color{red}{ 13}}^2-(2\cdot {\color{blue}{ 11}}\cdot {\color{red}{ 13}})cos(110^o)}\)
\

Answer 23

notice, the 110 is in degrees, so make sure your calculator is in Degree mode when getting the cosine

Answer 24

Ohh okay I did that before but I didn't get the sqrt of the whole thing. I got 19.693

Answer 25

Is that correct?

Answer 26

@jdoe0001

Answer 27

ohh yes it's
is 19.693

Answer 28

site was a bit lagged

Answer 29

So that's the final answer?

Answer 30

Thank you!

Answer 31

yw