Circle theorems Flashcards
1
Q
What is the ‘bow tie’ theorem’?
DO NOT USE THIS PHRASE!
A
Angles in the same segment are equal.
2
Q
The angle in a semicircle is…
From the end of a chord
A
90°
3
Q
The angle at the centre is…
A
Twice the angle at the circumference.
4
Q
What is a cyclic quadrilateral?
A
A shape with four sides where all four corners are touching the circumference of a circle.
5
Q
The opposite angles in a cyclic quadrilateral…
A
add to 180°
6
Q
What is a tangent?
A
A straight line that touches a circle in one place.
7
Q
A tangent meets a radius at
A
90°
8
Q
Tangents from the same point are
A
equal in length
9
Q
What do we mean by ‘bisects’
A
Splits in half
10
Q
Angles in a triangle add to
A
180°
11
Q
Base angles in…
A
isosceles triangles are equal
