* Circle Theorem *

* Circle Theorem *

1. Two radii and a chord make a isosceles triangle

2. The perpendicular from the centof a circle to a cord will always bisect the chord and split it in two equal angles

3. Angles formed from two points on the circumference are equal to the other angles in the same arc formed from those twp points

4. Angles formed by drawing lines from the ends of the diameter of a circle to its circumference form a right angle

5. A tangent to a circle is a straight line which touches the circle at only one point. It cant cross the circle just touch it.

6. A tangent to a circle forms a right angle with the circles radius, at the point of contact with the tangent

7. Angle at the center is twice that at the circumference of the circle by lines originating from the same points

8. alternate circle theorem- angles in a shape of a z are equal to each other

9. Area of a sector and arc length -a sector is part of the circle and to work out its are you work out the whole circles and then take a percentage of that which would be the angle of secotr over 360 (total)

   • The arc is the part of the circumference of the circle which is on the edge of the sector