# Lesson 5

Circles and Triangles

### Lesson Purpose

The purpose of this lesson is for students to identify, describe, and compare circles and triangles.

### Lesson Narrative

Students are also introduced to the geometric terms

**circle**and**triangle**. Students develop their intuitive understanding of circles and triangles. They may incorrectly identify shapes in this activity, such as identifying an oval as a circle. If this happens, acknowledge the similarities between the shapes (“This shape is curved like a circle, but it is not a circle.”) As students sort examples and non-examples of triangles in the second activity, they continue to build their informal understanding of what a triangle is.- Representation

- MLR8

Activity 2: Triangle Sort

### Learning Goals

Teacher Facing

- Identify, describe, and compare circles and triangles.

### Student Facing

- Let’s learn the names of some shapes.

### Required Materials

Materials to Gather

- 5-frames
- Collections of objects
- Colored pencils or crayons
- Counting mats
- Materials from previous centers

Materials to Copy

- Triangle Sort Cards

### Required Preparation

Activity 1:

Each student needs at least 2 different colored crayons or colored pencils.

Activity 2:

- Cut out triangle cards from the blackline master. Each group of 4 needs 1 set of cards.

Activity 3:

- Gather materials from:
- Which One, Stage 1
- Picture Books, Stages 1-3
- Bingo, Stages 1 and 2
- Shake and Spill, Stages 1 and 2

### Lesson Timeline

Warm-up | 10 min |

Activity 1 | 10 min |

Activity 2 | 15 min |

Activity 3 | 20 min |

Lesson Synthesis | 5 min |

Cool-down | 0 min |

### Teacher Reflection Questions

How did students think of triangles as they came into the lesson? In what ways did their understanding of triangles change upon completing the lesson?