The Student Room Group

Circle theorem

How do i do this


circle.JPG

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Reply 1
i know that PAD = 18

ABD and ADB = 180-72/2 = 54
Reply 2
AP=AB

What does this tell you about the triangle APB?

And what does that imply about the angles in the triangle?
So, you know that the triangle is ********* which means the angles are the ****.
Reply 4
Original post by notnek
AP=AB

What does this tell you about the triangle APB?

And what does that imply about the angles in the triangle?


They have to bee the same
Reply 5
Original post by shadab786ahmed
So, you know that the triangle is ********* which means the angles are the ****.


same
Reply 6
Original post by zed963
They have to bee the same

Well two of them are the same:

<APB = <ABP

Now you know the size of <PAB (90) so what are <APB and <ABP ?
Reply 7
Original post by notnek
Well two of them are the same:

<APB = <ABP

Now you know the size of <PAB (90) so what are <APB and <ABP ?


45
Reply 8
Its 117o, 90-72=18, APD=45 because the triangle is isololes. 18+45=63, 180-63=117.
(edited 11 years ago)
Reply 9
Original post by zed963
45

Good. Finally, look at triangle APD.

<APD = 45, <PAD = 18

So what is <PDA ?
Reply 10
Original post by notnek
Good. Finally, look at triangle APD.

<APD = 45, <PAD = 18

So what is <PDA ?


117!!!!
Original post by JoeFo
117!!!!


Do you object to the OP solving this for themselves
Reply 12
Original post by notnek
Good. Finally, look at triangle APD.

<APD = 45, <PAD = 18

So what is <PDA ?


117
Reply 13
how would i do this then

circle.JPG

part b
Original post by zed963
how would i do this then

circle.JPG

part b


You really need to start thinking for yourself

Sketch the diagram

Mark any angles that you know

Indicate any equal lines/angles
Reply 15
Original post by zed963
how would i do this then

circle.JPG

part b

117 is correct.

Have you made any progress with this question? What is <AOB?
Reply 16
Original post by JoeFo
117!!!!

You're like the annoying kid in a classroom who shouts out the answer before the teacher has finished going through a problem :smile:.
Original post by notnek
You're like the annoying kid in a classroom who shouts out the answer before the teacher has finished going through a problem :smile:.


Ahahaha +rep
Reply 18
Original post by TenOfThem
You really need to start thinking for yourself

Sketch the diagram

Mark any angles that you know

Indicate any equal lines/angles



would the answer be 56
Reply 19
Original post by zed963
would the answer be 56

Sorry, no.

Post your working.

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