Basic Trigonometry
Maths and statistics discussion, revision, exam and homework help.
-
- Reputation:
- Peer Of The TSR Realm
- Posts: 1,534
Re: Basic Trigonometrybrilliant! one question and sorry if it is a bit of a stupid one but the line r that you drew from the side AO to the middle you labelled it a right angle, how comes wouldn't the right angle be on the other side ?(Original post by raheem94)
See the diagram below:
Use sin in the blue triangle and you are done.
Spoiler:Show
Last edited by Roshniroxy; 28-04-2012 at 13:54. -
- Reputation:
- TSR Demigod
- Posts: 5,512
Re: Basic TrigonometryIt is a right angled triangle because it is a tangent to the circle.(Original post by Roshniroxy)
brilliant! one question and sorry if it is a bit of a stupid one but the line r that you drew from the side AO to the middle you labelled it a right angle, how comes wouldn't the right angle be on the other side ?
I don't understand what you mean by 'other side'? -
- Reputation:
- Peer Of The TSR Realm
- Posts: 1,534
Re: Basic Trigonometry(Original post by raheem94)
It is a right angled triangle because it is a tangent to the circle.
I don't understand what you mean by 'other side'?
-
- Reputation:
- TSR Demigod
- Posts: 5,512
Re: Basic TrigonometryNo, this angle won't be a right angle.
Remember tangents make an angle of 90degree with the radius of the circle, hence the other angle was a right angle.
So we know one angle is 90 degree and one is 30 degree, so this angle will be 180-(90+30)=180-120=60deg. -
- Reputation:
- Peer Of The TSR Realm
- Posts: 1,534
Re: Basic TrigonometryThank you for this !(Original post by raheem94)
No, this angle won't be a right angle.
Remember tangents make an angle of 90degree with the radius of the circle, hence the other angle was a right angle.
So we know one angle is 90 degree and one is 30 degree, so this angle will be 180-(90+30)=180-120=60deg.
