Circle Rules

Question 1

1

Answer 1

A tangent and a radius meet at 90o
-> a tangent is a line that just touches a single point on the circumference of a circle. A tangent always makes an angle of exactly 90o with the radius it meets at this point

Question 2

2

Answer 2

Two radii form an isosceles triangle.
-> unlike other isosceles triangles they don’t have the little tick marks on the sides to remind you that they are same- the fact that they are both radii is enough to make it an isosceles triangle.

Question 3

3

Answer 3

The perpendicular bisector of a chord passes through a the centre of the circle.
-> a chord is any line across a circle. and no matter where you draw a chord, the line that cuts it exactly in half (at 90o) will go
Through the centre of the circle

Question 4

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Answer 4

The angle at the centre of a circle is twice the angle at the circumference.
-> the angle subtended at the centre of a circle is e

Question 5

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Answer 5

The angle in semi circle is 90o-> a triangle drawn from the two ends of a diameter will always make an Aggie of 90o where it hits the circumference.

Question 6

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Answer 6

Angles in the same segment are equal -> all triangles drawn from a chord will have the same angle where they touch the circumference, also the two angles on opposite sides of chord adds up to 180o