12 1 Lines That Intersect Circles Rigor Identify

12 -1 Lines That Intersect Circles Rigor : Identify tangents, secants, and chords and use properties of tangents to solve problems. Relevance: Solve problems involving planets Holt Mc. Dougal Geometry

12 -1 Lines That Intersect Circles • The interior of a circle is the set of all points inside the circle. • The exterior of a circle is the set of all points outside the circle. Holt Mc. Dougal Geometry

12 -1 Lines That Intersect Circles Holt Mc. Dougal Geometry

12 -1 Lines That Intersect Circles Example 1: Identify each line or segment that intersects P. chords: secant: tangent: diameter: radii: Holt Mc. Dougal Geometry

12 -1 Lines That Intersect Circles Holt Mc. Dougal Geometry

12 -1 Lines That Intersect Circles A common tangent is a line that is tangent to two circles. Draw a radius from each circle’s center to the point of tangency. What do you notice? Holt Mc. Dougal Geometry

12 -1 Lines That Intersect Circles Turn in your workbook to page 495 and highlight this theorem Note: The converse of this theorem is also true! Holt Mc. Dougal Geometry

12 -1 Lines That Intersect Circles Example 2: Space Early in its flight, the Apollo 11 spacecraft orbited Earth at an altitude of 120 miles. What was the distance from the spacecraft to Earth’s horizon rounded to the nearest mile? The radius of the Earth is about 4000 miles. Holt Mc. Dougal Geometry

12 -1 Lines That Intersect Circles Example 3: View from the Summit Kilimanjaro, the tallest mountain in Africa, is 19, 340 ft tall. What is the distance from the summit of Kilimanjaro to the horizon to the nearest mile? 5280 ft : 1 mile Holt Mc. Dougal Geometry

12 -1 Lines That Intersect Circles Last concept for this section! Holt Mc. Dougal Geometry

12 -1 Lines That Intersect Circles Example 4: HK and HG are tangent to F. Find HG. Holt Mc. Dougal Geometry

12 -1 Lines That Intersect Circles 12 – 1 Classwork • Heading: 12 -1 Textbook pg 797 – 799 # 6 – 12, 15, 26, 27 Holt Mc. Dougal Geometry