#1 Non-Circle Theorems
These are not circle theorems, but are useful in questions involving circle theorems.
50
130
?
Angles in a quadrilateral add up to 360.
Base angles of an isosceles triangle are equal.
Bro Tip: Remember the wording in the black boxes, because you’re often required to justify in words a particular angle in an exam.
This result is that any triangle with one vertex at the centre, and the other two on the circumference, must be isosceles.
Opposite angles of cyclic quadrilateral add to 180
Angles in same segment are equal
Angle at centre is twice angle at circumference
Lengths of the tangents from a point to the circle are equal
Base angles of isosceles triangle are equal.
Angles of quadrilateral add to 360
Reveal
Opposite angles of cyclic quadrilateral add to 180
Angles in same segment are equal
Angle at centre is twice angle at circumference
Lengths of the tangents from a point to the circle are equal
Base angles of isosceles triangle are equal.
Angles of quadrilateral add to 360
Reveal
Opposite angles of cyclic quadrilateral add to 180
Angles in same segment are equal
Angle at centre is twice angle at circumference
Lengths of the tangents from a point to the circle are equal
Base angles of isosceles triangle are equal.
Angles of quadrilateral add to 360
Reveal
Opposite angles of cyclic quadrilateral add to 180
Angles in same segment are equal
Angle at centre is twice angle at circumference
Lengths of the tangents from a point to the circle are equal
Base angles of isosceles triangle are equal.
Angles of quadrilateral add to 360
Reveal
Opposite angles of cyclic quadrilateral add to 180
Angles in same segment are equal
Angle at centre is twice angle at circumference
Lengths of the tangents from a point to the circle are equal
32
?
Base angles of isosceles triangle are equal.
Angles of quadrilateral add to 360
Reveal
Opposite angles of cyclic quadrilateral add to 180
Angles in same segment are equal
Angle at centre is twice angle at circumference
Lengths of the tangents from a point to the circle are equal
31
?
Base angles of isosceles triangle are equal.
Angles of quadrilateral add to 360
Reveal
Click to Start Bromanimation
...is equal to the angle in the alternate segment
136
68
Angle at centre is double angle at circumference.
Alternate Segment Theorem.
?
?
?
?
?
?
Source: IGCSE Jan 2014 (R)
?
?
?
?
?
?
Adding opposite angles:
a + b + 180
– a – b = 180
3: Angles in triangle add up to 180.
?4
4: But any other angle in the same segment will be the same.
Если не удалось найти и скачать доклад-презентацию, Вы можете заказать его на нашем сайте. Мы постараемся найти нужный Вам материал и отправим по электронной почте. Не стесняйтесь обращаться к нам, если у вас возникли вопросы или пожелания:
Email: Нажмите что бы посмотреть