Download Math 9 Study Guide Unit 8 Unit 8 - Circle Geometry Pythagorean

Math 9
Study Guide
Unit 8
Unit 8 - Circle Geometry
Pythagorean Theorem
a2 + b2 = c2 (where c is always the hypotenuse)
Properties of Tangents to a Circle
A line that intersects a circle at only one point is a TANGENT to the circle. The point
where the tangent intersects the circle is the POINT OF TANGENCY. Line AB is a
tangent to the circle with centre O. Point P is the point of tangency.
Properties of Chords in a Circle
Chord: a line segment that joins 2 points inside a circle
Diameter: a chord through the centre of a circle
Math 9
Study Guide
Unit 8
Properties of Angles in a Circle
Arc: section of the circumference of a circle
Minor Arc: shorter section
Major Arc: longer section
Central Angle: angle formed by joining endpoints of an arc to the center of a circle.
The sum of all the central angles in a circle is 3600
Inscribed Angle: angle(s) formed by joining the endpoints of an arc to any point on
the circle.
The inscribed and central angles in this circle are subtended by the same minor arc.
In the circle below the inscribed angle (ACB) and central angle (AOB) are subtended
by the minor arc AB.