Similar Triangles in Circle-Secant (or Circle-Secant-Tangent) Diagrams
Related Topics:
Lesson Plans and Worksheets for Geometry
Lesson Plans and Worksheets for all Grades
More Lessons for Geometry
Common Core For Geometry
New York State Common Core Math Geometry, Module 5, Lesson 16
Student Outcomes
- Students find βmissing lengthsβ in circle-secant or circle-secant-tangent diagrams.
Similar Triangles in Circle-Secant (or Circle-Secant-Tangent) Diagrams
Classwork
Opening Exercise
Identify the type of angle and the angle/arc relationship, and then find the measure of π₯.
Exploratory Challenge 1
Measure the lengths of the chords in centimeters, and record them in the table.
Exploratory Challenge 2
Measure the lengths of the chords in centimeters, and record them in the table
Lesson Summary
THEOREMS:
- When secant lines intersect inside a circle, use π β π = π β π.
- When secant lines intersect outside of a circle, use π(π + π) = π(π +π).
- When a tangent line and a secant line intersect outside of a circle, use π2 = π(π + π)
Relevant Vocabulary
SECANT TO A CIRCLE: A secant line to a circle is a line that intersects a circle in exactly two point
Check out our most popular games!
Fraction Concoction Game:
Master fractions in the lab: mix, add, and subtract beakers to create the perfect concoction!
Fact Family Game:
Complete fact families and master the link between addition & subtraction and multiplication & division.
Number Bond Garden:
Clear the board by matching number pairs that sum to ten in this garden-themed mental math puzzle.
Online Addition Subtraction Game:
Practice your addition and subtraction skills to help the penguin find its mummy.
Penguin Solitaire
Penguin Solitaire is a fun game that aims to move all cards to the foundations to build four full sequences. There are two versions here: Penguin (Tuxedo) and Penguin (Original).
We welcome your feedback, comments and questions about this site or page. Please submit your feedback or enquiries via our Feedback page.