Rules

Question 1

What are the circle theorems?

Answer 1

• angle at centre = twice that at the circumference (arrowhead)
• angles from the same arc in the same segment are equal (bow tie rule)
• triangle formed in a semi circle has a 90 degree angle at circumference
• opposite angles in a cyclic quadrilateral sum to 180
• the radius perpendicular to a chord bisects the chord
• the tangent is perpendicular to the radius
• Two tangents drawn from a point on the circle are equal length when they join
• alternate segments are equal to the angle on the tangent

Question 2

180(n-2) is the rule for what?

Answer 2

The total of the sum of the interior angles

Question 3

And interior angle + an exterior angle of the same regular polygon is what?

Answer 3

180