Lines and Circles for grade ten 10.1.pptx

Mathematical rules presentation for students and teachers

1. Circles Geometry Chapter 10 10.1 Lines and Segments that Intersect Circles

2. Objective After these 2 sessions, students will be able to: Draw a circle either by being given the radius or the diameter. Identify special segments and lines that intersect circles. U se properties of tangents to solve problems.

3. What do you know about a circle? Give me a real-life example that has a circle form

4. Definitions Circle: I t is a two - dimensional figure which is round in shape. All the points on the boundary of the circle are equidistant from a point inside the circle which is known as the center of the circle It is written as C ( center, radius) Radius (r): I t is the distance from the center of the circle to the edge . Chord: It is a line segment that connects two points on a circle. Diameter ( d ): It is a chord that goes through the center of the circle (longest chord = 2 radii )( d = 2 r)

5. What is the radius of a circle of center O if the diameter is 8 cm? D raw it.

6. Relative positions of a line and a circle Secant: A line that intersects a circle twice Tangent: A line that intersects a circle once at a point called a point of tangency .

7. What word best describes ? What word best describes ? Name a tangent and a secant .  

8. Intersection of Circles Two circles can intersect in 2 points 1 point No points

9. Tangent Lines Tangent lines are perpendicular to radius. Theorem: Two tangents issued from one point outside the circle to the same circle are equal.

10. Is tangent to the ? is tangent to the . Find the value of r .   5

11. Find the value of x .

12. Just for fun What is the number of circles?