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# Any mathematicians here?

Need help working out the following question please.

See post below.
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Original Poster

Original Poster

shirishtiwari01;8806824

That's short for Opposite side.

I got 34.7m. Not 100% sure though.

I get 34m but hey Im only a rocket scientist! :whistling:

i believe You need to work out the middle line length using cosine rule on bottom triangle then use the sine rule to calculate the lenght you want.
Could be easier way but not sure.

all i get is a headache looking at it, so my answer is painkillers lol

Original Poster

Spammed;8806915

I got 34.7m. Not 100% sure though.

scottydont;8806927

I get 34m but hey Im only a rocket scientist! :whistling:

Did you guys use cosine and sine rule?

Use cosine rule for lower triangle:

QS= root (27 squared +50 squared - (2*27*50*cos82)

This gives QS= 53.4m

Now use sine rule for upper triangle:

PS= (53.4*sin38)/sin118

This gives PS=37.2m

Hope this helps.

Original Poster

ErrorOperator;8806937

i believe You need to work out the middle line length using cosine rule … i believe You need to work out the middle line length using cosine rule on bottom triangle then use the sine rule to calculate the lenght you want.Could be easier way but not sure.

I was trying to use sohcahtoa :thinking: ..will try again

Is that gcse?

SQ = sqrt(SR^2 + QR^2 - 2* SR * QR * cos(82)) = sqrt ( 50^2 + 27^2 -2 *50*27*cos(82)) ~= 53.416m using Cosine rule

Then use the sine rule
Sin(38)/PS = Sin(118)/53.416
=> PS = 53.416 * Sin(38) / Sin(118) = 37.246m

Edit: Doh, too slow

Yes sorry It's 37. I accidentally used sin 110 instead on 118. I don't think you can use soh cah toa for this as there's no right angle in either triangle.

I was trying to use sohcahtoa ..will try again

thats for right angle triangles

if you to do the question yourself, the equation they are using is :
b^2=a^2+c^2-2acCosB

you can count me out ;-) :whistling:

Original Poster

Met-Cast;8807025

Is that gcse?

Yes. How did you guess?

Original Poster

Very well explained guys repped you! And thanks