Inscribed Polygons

By Michael Rust  • Pam Heckel

Grade Level
10th-11th
Subject Area
Algebra 2 (Integrated Math)
Duration
55 minutes
Background Knowledge

Students should be familiar with basic shapes such as triangles and circles, as well as trigonometric concepts such as perpendicular bisectors. Other concepts needed are midpoint and distance equations, Pythagorean theorem, and slope of a line.

Author
Michael Rust & Pam Heckel
 
Summary
Working in groups of two, students complete an exploration activity to determine whether a circle can be drawn through the vertices of any triangle. The students will take notes on the theory of inscribed triangles and then participate in a guided example on the board/overhead. Students then work on problems to reinforce these concepts.
 
Objectives

Students will be able to
1. understand that it is always possible to circumscribe a circle about a triangle
2. identify chords of a circle
3. identify that the perpendicular bisector of a chord of a circle passes through the center of a circle
4. apply these concepts to problems

 
Mateirals Required

Rulers, compasses

 
Ohio Standards

Mathematics

Grade 10
Geometry and Spatial Sense

C. Recognize and apply angle relationships in situation involving intersecting lines,
perpendicular lines and parallel
D. Use coordinate geometry to represent and examine the properties of geometric figures
E. Draw and construct representations of two- and three-dimensional geometric objects using a variety of tools, such as straightedge, compass, and technology
G. Prove or disprove conjectures and solve problems involving two- and three-dimensional objects represented within a coordinate system.

Mathematical Processes

A. Formulate a problem or mathematical model in response to a specific need or situation, determine information required to solve the problem, choose method for obtaining this information, and set limits for acceptable solution
B. Apply mathematical knowledge and skills routinely in other content areas and practical situations.
computerized microscopes).

Documents
Lesson Plan worddoc