Everything About Circle Theorems - In 3 minutes!

This is a graphic, simple and memorable way to remember the difference from a chord or a tangent or a segments and sectors! I made this after struggling to understand it myself, once i got to grips with it i decided to help others who were also stuck.. so this video was created...

This video includes Perpendicular bisectors of any chord
the angles in a semi-circle,
what happens when a tangent and a radius meet,
Angles that are in the same segment and how different they are, the circumference subtended by the same arc,
the meaning of subtended,
lengths of two tangents and finally the angle between a tangent and a chord.. aka Alternate Segment Theorem.

I re-uploaded this video because the last one had some glitches so here we are againn....

FOR THE QUESTION IF YOU ARE STUCK
okay so angle A is 55degrees. this is because the whole isosceles triangle adds up to 180degrees, you now take 70degrees from this because the angle on the far right hand side is 70degrees. this leaves us with 110degrees and you divide it by two (due to it being isosceles triangle) so angle A is 55degrees.

if you go to 1:07 this explains the next part on why there is a 90degree angle on top of angle B.
 you take 55degrees from that 90degrees because part of the right angle overlaps the first isosceles triangle (on the right hand side) and we have previously worked out that, that angle is 55degrees, this leaves us with 35degrees.

now times that 35 by 2 which gives you 70degrees, take that answer AWAY from 180degrees because as you can see angle D is within ANOTHER isosceles triangle which means all the angles within the triangle add up to 180degrees.

because angle D is within that triangle, angle D and the angle at the bottom right of the Isosceles triangle will EQUAL to the same amount.
now divide the 110degrees by 2 to give you 55degrees.

[EasyAsPi]

*MUST READ* Number six in this video apears to be out of proportion and I did not realise. the arrow head shape MUST join in the centre of the circle not just anywhere. please note that the angle at the CENTRE of the circle is double that at the tip of the arrow.

in the video it is slightly below the centre of the circle.

[MarcusCockerill]

Evening chaps, how's the last minute cramming going?

[harmankaurw]

To all the people having exam tomorrow and are here for last minute studies BEST OF LUCK!

Edit:Thanks for the likes, I hope everybody scores their highest marks

[idk-troq]

I just learnt all the theorems in 4 minutes and 10 seconds and was able to answer the final question correctly. This is a really good video lmao way better than any of my teachers could've done

[minurso]

i’m not here for the math exam, i’m here because i’m trying to make sense of quarantine math class

[Yguy]

Honestly wasn't gonna see this simply because I thought this was one of those videos teaching impossible things in just 5 mins. I was, however, mind-blowned. I got the whole jist of the chapter. All I need now is to read my textbook and do questions just to see how much I got it. Amazing work, thanks!

[TaySwiftnBTRLuver]

the facts are helpful but the music is distracting 😅😅

[jeevacation]

School: 15 days circle theorems
Youtube: 4 min 10 sec circle theorems

[alaricwitoyo]

Also, for 1:47, it doesn't have to be an arrow shape.
It's just that all angles from the centre of the circle will ALWAYS be twice (2x) the angle at the circumference, as long as they are subtended by the same arc. The angle at the circumference can move around the circumference, making shapes that don't have names.

[eddybertani]

Since you have an exam tomorrow, stop reading the comments

[skyelee]

Anyone last minute studying for the exams?

[hirokosato]

I have an exam in an hour and I needed a quick revision and this was the perfect one, sending it to all my classmates
thank you brother

[lumosss]

For that question at the end, there is a much quicker way to do it.
A= (180-70) / 2 = 55 degrees
Therefore, D = 55 degrees because of alternate segment theorem

Correct me if I'm wrong :3

[bigmich]

Who else is going thru the exam leaving everything in God's hands cause they still don't understand??😂😂

[Arv_]

when your teacher spends 2 weeks explaining this, and no one understands, then this guy explaines it in 4 mintues and 10 seconds and I understand it

[aarononuorah]

literally no one
not a single soul on the earth
People in the comment section:
'AnYoNe HeRe FoR tHe MaTh ExAmS'

[shounakghosh]

Here's one more little tip: in the last question, the quadrilateral ABC and the 70° point make up a cyclic quadrilateral (proof left as an exercise) so C is 180° - 70° = 110°. Then you can proceed as in the video to get D = 110° / 2 = 55°.

[joekc]

Me: ok this is three minutes long surely I can concentrate.

Also me vining to the music: DE DE DE DA DA DA DO DO DO DOO DO DO DA DE DE DE DA DA DO DO DO

[ashutoshanand]

All youtubers are adding faded theme song in the background 😂
Strange very Strange 😈

[thatnerd]

You're bursting with potential mate:D Tone down the music?