Circle Theorem - Term 1

Question 1

What does a tangent do?

Answer 1

A tangent touches the edge of the circle at one point

Question 2

What is the rule for tangents and a radius?

Answer 2

A tangent and a radius meet to make 90*

Question 3

What is the rule for tangents on an extended point?

Answer 3

Tangents from an extended point to a circle are equal in length

Question 4

What is the rule for angles on an arrowhead shape?

Answer 4

The angle at the centre is twice the size of the angle at the circumference

Question 5

When does the angles on an arrowhead rule apply?

Answer 5

An angle must be in the centre and the other three are touching the circumference of the circle

Question 6

What is the rule for angles in a segment? (Bowtie shape)

Answer 6

Angles in the same segment are equal

Question 7

When does the angles on a (segment) bowtie rule apply?

Answer 7

All points must be touching the circumference

Question 8

What is the rule for one angle in a triangle in a semicircle?

Answer 8

The angle in a semicircle is always 90*

Question 9

What do we look for in angles in a semicircle?

Answer 9

One length of the triangle must go through the centre of the circle. All vertices are touching the circumference

Question 10

What is the rule for angles in a cyclic quadrilateral?

Answer 10

Opposite sides in a cyclic quadrilateral add up to 180*

Question 11

What do you look for to identify a cyclic quadrilateral?

Answer 11

All points of the quadrilateral must be touching the circumference

Question 12

What are the two rules of bearings?

Answer 12

Measured clockwise from north

Must always have 3 digits

Question 13

I calculate that the bearing of point A to point B is 70*. How do I write this as a bearing?

Answer 13

070* because bearings must always have three digits