Presentation on theme: "Warm up 2 – 18 evens only. This will be graded in 10 minutes. 2.79"— Presentation transcript:
1 Warm up 2 – 18 evens only. This will be graded in 10 minutes. 2.79 27.9361.78138.47.16309.4°107 °°°
2 9.2 Tangents and Secants Tangents and secants are LINES. A tangent line intersects the circle at exactly ONE point.A secant line intersects the circle at exactly TWO points.
3 A little extra information The word tangent comes from the Latin word meaning to touchThe word secant comes from the Latin word meaning to cut.
4 Important Theorems Tangent Theorem: If a line is tangent to a circle, then the line is perpendicular to a radius of the circle drawn to the point of tangency.The line AB is tangent to circle C at B.How could we prove that segment CB and line AB are perpendicular?
5 Converse of the Tangent Theorem Go waaaayyy back… how do we get a converse statement?What would be the Converse of the Tangent Theorem?If a line is perpendicular to a radius of a circle at its endpoint on the circle, then the line is tangent to the circle.
6 Radius and Chord Theorem A radius that is perpendicular to the chord of a circle bisects the chord.QR = 3What is the measure of RS?XR = 7 and WR = 2Find the missing measures of the remaining segments.RZ =RY =XW =WZ =XZ =76.713.4
7 I need 2 volunteers to hand out whiteboards and markers. Let’s PracticeI need 2 volunteers to hand out whiteboards and markers.