math homework help!

trigonometry
hi im stuck on question 4b

traingle for the question
http://i204.photobucket.com/albums/b...orkmath002.jpg


question 4b
http://i204.photobucket.com/albums/b...orkmath001.jpg


could you also write down all working thanks :P

As all thee sides are the same size, then a is 60 degrees.

And i've got no idea whatsoever for question b, because you haven't supplied enough info :)

We need the whole of Q4, and tomo4 is correct with 60 degrees. It's an equilateral triangle.

OHhh the first image is Q4 :p

I'm not telling you the answers, but I'll give you hints

a) It's an equilateral triangle, so all the angles are the same

b) I'm assuming the triangle is the doorway. If you imagine there was a vertical line from the top of the triangle, to the mid point of the base of the triangle, you split it into 2 right angle triangles. You know the angle from part a, you know hypotenuse is 3m, and you are trying to find the height, which is the opposite, so from sohcahtoa it's going to sine that you need to use.

Split the trignale down the middle so you have 2 right angled triangles.

So you have HYP: 3m, BOTTOM: 1.5m, and unknown.

Work it out using TRIG:

a^2 + b^2 = c^2

I have sort of forgotten all my maths, as I won't need it again lol, but, you I think you can use one of the Sine/Cos/Tan rules if you split the triangle in half. That way you have the bottom length, 1.5 which is the adjacent (spelt wrong), and the Hypothesis which is 3 Cm and the angle which is 60 Degrees. I might be making it harder than it is though. Mind if I ask what Year you are in? That way it is easier to say if I am completly wrong lol.

sorry for my abismal paint skills
x
http://img111.imageshack.us/img111/3123/loljhj6.th.png

Sorry I haven't the slightest clue, but always read above ;)

trig is a2 + b2 = c2 if c is the hypotenuse (longest side)

if not its a2 - b2 = c2

am not telling you because you need to learn it because if people tell you the answers you will never understand it

a) Equilateral triangles always have 60° angles.
b) You don't even need trig for that, it's pythagoras:

If you halve the triangle, you have two right angled triangles. Then you have 3 as the hypotenuse, 1.5, and h.
h² + 1.5² = 3²
h² = 3² - 1.5²
h² = 9 - 2.25
h² = 6.75
h = √6.75
h = 2.5980762113533159402911695122588

Unless they actually want you to use trig anyway - if that's the case:

http://i279.photobucket.com/albums/k...RIG-HELP-1.jpg

You know the hypotenuse, adjacent, and you want the poosite angle, so SOH CAH TOA - Use the sin function.
sin60° = Opposite/Hypotenuse
sin60° = Opposite/3
sin60° x 3 = Opposite
0.866025403 x 3 = Opposite
Opposite = 2.5980762113533159402911695122588
h = 2.5980762113533159402911695122588

Remember, you don't need trig for a right angled triangle if you know 2 of the sides.

Several of you are describing the pythagoras theorem as trig... THey're not the same.

umm, dont meen to sound rude but trig uses sine, cosine and tangent. the one using squared is pythag theorm. just a pointer :P