Question

solve each triangle . round your answers to the nearest 10th.

in ABCtriangle,a=14cm, b=9cm, c=6cm
in QRPtriangle, q=12in, p=28in, r=18in
inDEFtriangle, e=16yd, d=12yd, f=17yd
in QRPtriagle, p=28km, q=17km, r=15km

Answer 1

I guess they want you to find all the angles, right?

Answer 2

yess

Answer 3

Ok, so there is a step-by-step procedure for this given here: http://en.wikipedia.org/wiki/Solution_of_triangles#Three_sides_given_.28SSS.29

You will have to use the law of cosines (the formula given will give you the angle C).
THEN use the law of sines to find the angles A and B.

FIRST STEP -- just solve for c. Lemmie know what you get. :)

Answer 4

ok, but r we doing the first problems because my problem is drawing it

Answer 5

Oh, you're supposed to draw it and then get your answers from the drawing? (like, with a ruler, compass, protractor?)

Answer 6

yea like im supposed to draw a triangle thats what i was confused at

Answer 7

Ahh, ok. What tools do you have to draw them with? (are you using geogebra, geometer's sketchpad, or other software, or are you drawing them by hand with compass, ruler, protractor, etc?)

Answer 8

it doesnt matter its freehand

Answer 9

Ok, well, I mean, if you want an accurate picture you should at least use a ruler and compass -- or use geogebra to generate a nice picture. Otherwise just draw any old triangle with three sides of different lengths and make sure the longest side is labeled as such. :-p

Answer 10

okay so it doesnt matter how i label it

Answer 11

so how do i find the angles

Answer 12

i get stuck on finding the angles because i know how to do it but i get to a point where i stop

Answer 13

It would be kinda silly to label the smallest side with the longest length... at least try to get that accurate. :-p

So for...
ABC triangle,a=14cm, b=9cm, c=6cm

DRAWING STEPS

1) Draw a triangle with three different side lengths.
2) Label the LONGEST side as a = 14cm
3) Label the SMALLEST side as c = 6cm.

FINDING THE ANGLE STEPS

To find angle C (the angle opposite the side labeled c) fill in the blanks...

c^2 = a^2+b^2-2*a*b*cos(C)

QUESTION ==> Do you know how to use arccos ? (inverse cosine)?

Answer 14

not really

Answer 15

im stuck

Answer 16

Ok. So let's take a step back then.

Say you have 1 = sin(x)

And you wanna find what x is... but you can't like "divide by sin" that doesn't make sense.
You have to "UNDO" whatever the function "sin' DID to the angle x to find the result 1...

so

arcsin(1) = x

Try it. Input arcsin(1) ... or it might be written as .... sin^(-1)(x) and see what comes out with your calc.

Answer 17

okay but before i do that for this particular problem would it be sin of x/14=sin9/31

Answer 18

What were the steps leading up to that? Also, do you mean sin(9) divided by 31 or sin(9/31) ? Where did 31 come from?

Answer 19

no i was doing an example because i need to fill in the numbers in order to find the angle but imconfused on that