trigonometry problem

Original post by Chittesh14

Yeah, well I got the same answer too. 36.9, always round the answer to 3 significant figures. Nevertheless, same answer.

Ratio between 2 hypotenuses, 2M to 4M = 1:2.
So, BC and CD's length's will be split up in the ratio 1:2 aswell. BC = 1.2m and CD = 2.6m.

SOHCAHTOA
Angle we're finding = BAC
Opposite side = BC
Hypotenuse = AC

sin-1 (1.2 / 2) = 36.86989765
= 36.9 (3 s.f)

Cool, I just used the sine rule and similar triangles.

Reply 7

Original post by Dizgurl

Cool, I just used the sine rule and similar triangles.

Oh right lol. Yeah, the sine rule was possible but it's SOHCAHTOA is more preferred as we are dealing with Right-Angled Triangles. Nevertheless, nice!

Reply 8

Original post by Chittesh14

Oh right lol. Yeah, the sine rule was possible but it's SOHCAHTOA is more preferred as we are dealing with Right-Angled Triangles. Nevertheless, nice!

Thanks!
Ok, Ill use SOHCAHTOA next time.... :smile:

Reply 9

Original post by Chittesh14

Ratio between 2 hypotenuses, 2M to 4M = 1:2.
So, BC and CD's length's will be split up in the ratio 1:2 aswell. BC = 1.2m and CD = 2.6m

Even assuming that you mean 2.4 instead of 2.6

I do not agree with this premise

Reply 10

Original post by Dizgurl

Thanks!
Ok, Ill use SOHCAHTOA next time.... :smile:

It is fine to use sine and cosine rules even in right angled triangles

Sadly you do not have the correct answer for this question because the base is not split into 1.2 and 2.4

Reply 11

Original post by TenOfThem

It is fine to use sine and cosine rules even in right angled triangles

Sadly you do not have the correct answer for this question because the base is not split into 1.2 and 2.4

Ok, its fine, at least i tried... :smile:

What is the answer please explain.

Reply 12

Original post by Dizgurl

Ok, its fine, at least i tried... :smile:

What is the answer please explain.

There is quite a bit more to it as you need to turn the right hand triangle in order to get similar triangles

Reply 13

Original post by TenOfThem

Even assuming that you mean 2.4 instead of 2.6

I do not agree with this premise

Yeah, I meant 2.4 cm. Just wondering then, what would you have done to find out the length of the smaller triangle of the 2? As in, how would you explain that the length is 1.2 cm?

Reply 14

Original post by Chittesh14

Yeah, I meant 2.4 cm. Just wondering then, what would you have done to find out the length of the smaller triangle of the 2? As in, how would you explain that the length is 1.2 cm?

That length is not 1.2

Reply 15

Original post by TenOfThem

That length is not 1.2

In the previous post, i meant "m" not "cm" and what is it then? :/. I want to know where I went wrong.

Reply 16

Original post by Chittesh14

In the previous post, i meant "m" not "cm" and what is it then? :/. I want to know where I went wrong.

It isn't 1.2 at all

Your idea that the 3.6 needed to be in the ratio 1:2 is incorrect

Those two sides are not similar sides

Reply 17

Original post by TenOfThem

It isn't 1.2 at all

Your idea that the 3.6 needed to be in the ratio 1:2 is incorrect

Those two sides are not similar sides

Oh right. Okay, but then what would the answer to it be?
My answer is correct, but the formula is wrong. So then, what would the actual formula be & what is the length of the side 'BC'?

Reply 18

Original post by Chittesh14

Oh right. Okay, but then what would the answer to it be?
My answer is correct, but the formula is wrong. So then, what would the actual formula be & what is the length of the side 'BC'?

Your answer is not correct

You can either use Pythagoras or Harmonic Form to solve the problem

It would be interesting to see where the question came from

Reply 19