# TG-Grade 2 Investigating Right Angles

Submitted by:

Susan Montry

Date:

3-16-10

Edited by:

Michelle Pettit

Date:

4/1/10

Unit Name: Team Geometry

Unit Length: 5 weeks

Overview: Students explore the geometry in sports by investigating right angles on sports fields

DESIRED RESULTS

TEKS and SEs

(2.7) Geometry and spatial reasoning. The student uses attributes to identify two- and three-dimensional geometric figures. The student compares and contrasts two- and three-dimensional geometric figures or both.

The student is expected to:

(A) describe attributes (the number of vertices, faces, edges, sides) of two- and three-dimensional geometric figures such as circles, polygons, spheres, cones, cylinders, prisms, and pyramids, etc.;

(B) use attributes to describe how 2 two-dimensional figures or 2 three-dimensional geometric figures are alike or different; and

Critical Vocabulary

angle, vertex, vertices, right angle, protractor, face, edge

Enduring Understandings (Big Ideas)

Vertices are angles that can be measured. A right angle is 90 degrees.

Essential Questions

What is a solid shape? What is an angle? What is a vertex?

Learning Goals and Objectives

Students will be able to identify and measure right angles in the classroom.

Materials Needed

Partners need a clipboard, paper, pencil, protractor

ASSESSMENT PLAN

Students investigate right angles in the classroom and correctly identify right angles in the classroom.

Other Evidence

LEARNING PLAN

Engage: Brainpop Jr. Math: Geometry: Solid shapes. Review names of solid shapes.

Review faces, edges, vertex, and vertices. Introduce that the corner is an angle that can be measured. Introduce the right angle and how it is shaped.

Explore: Students partner up with a clipboard, paper, and pencil to walk around the classroom and record examples of right angles.

Explain: Introduce the protractor and how it can measure a right angle and the degrees in a right angle. Demonstrate on the overhead how a protractor is used to measure. Give each pair of students a protractor and ask them to go back and measure to be sure the items they listed were right angles.

Elaborate: Have students share examples of what they found. Discuss what they found that turned out to not be right angles. Compare and discuss answers.

Evaluate: Individually students give a new example of a right angle in/around the classroom and one angle that isn’t a right angle. Students reason why it is or isn’t a right angle.

Time

10 minutes

5 minutes

10 minutes

5 minutes

5 minutes

10 minutes

Extension: Does a circle or an oval have right angles? Why or why not? Can you draw a triangle that has one right angle? Two right angles? Three right angles? Draw and prove your answers.

Modifications: Students may need a picture of a right angle to take with them as they search the room for examples before they explore with a protractor.