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# Angles Tweet

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IMPORTANT: You must wait until midnight (morning exams)/4.30AM (afternoon exams) to discuss Edexcel exams and until 1pm/6pm the following day for STEP and IB exams. Please read before posting, including for rules for practical and oral exams. 28-04-2013
1. Angles
How would I prove this.

Angles.bmp
2. Re: Angles
What is <RQT ?

Then what is <TQU in terms of x?

Finally, what is QTU in terms of x?
3. Re: Angles
Look at shape its "S" angles.

so STQ = TQR

Therefore TQU = 100-X

As it is an isoceles triangle as 2 sides are same so the adjacent angle QUT is also 100-X

Therefore to find angle QTU we do:

Sum of angles in triangle = 180 degrees

=180-(100-x)+(100-x)

=180-(200-2x)

=-20-2x

=(2x-20)degrees
4. Re: Angles
(Original post by wenger16)
Look at shape its "S" angles.

so STQ = TQR

Therefore TQU = 100-X

As it is an isoceles triangle as 2 sides are same so the adjacent angle QUT is also 100-X

Therefore to find angle QTU we do:

Sum of angles in triangle = 180 degrees

=180-(100-x)+(100-x)

=180-(200-2x)

=-20-2x

=(2x-20)degrees

It is one of the rules of this forum not to post solutions. Plus in this case it's much more beneficial for the OP to work through the problem himself considering his exam is coming up very soon.
5. Re: Angles
(Original post by wenger16)
Look at shape its "S" angles.

so STQ = TQR

Therefore TQU = 100-X

As it is an isoceles triangle as 2 sides are same so the adjacent angle QUT is also 100-X

Therefore to find angle QTU we do:

Sum of angles in triangle = 180 degrees

=180-(100-x)+(100-x)

=180-(200-2x)

=-20-2x

=(2x-20)degrees
How do you get from -2x to 2x
6. Re: Angles
Are you getting the 100-x from the z angle on STQ
7. Re: Angles
(Original post by zed963)
How do you get from -2x to 2x
Its equal you can always reverse signs.

or think of it as multiplying whole thing by -1.

ye its z angle so you know its 100-x
8. Re: Angles
(Original post by wenger16)
Its equal you can always reverse signs.

or think of it as multiplying whole thing by -1.

ye its z angle so you know its 100-x
Thanks for that.
Much appreciated.
9. Re: Angles
(Original post by wenger16)
Its equal you can always reverse signs.
Hope my bank doesn't agree.

Actually you made a mistake multiplying out the bracket.

(Original post by wenger16)

=180-(200-2x)

=-20-2x
180-(200-2x) = 180-200 + 2x = -20 + 2x