Session 1 – TrianglesLearning Objectives

In this session, Mathematicians will:O Use geometric thinking to solve visualization

problems.O Use mathematical language to express ideas

and to understand the ideas of others.O Construct the basic objects of geometry.O Classify triangles according to some of their

features

Task 1: QUICK IMAGES You will need a piece of paper and pencil/pen. You'll see an image briefly and then try to draw it from memory on a piece of paper. You will have 3 seconds to view.

Part 1: What is Geometry?

Task2: BUILDING FROM DIRECTIONS

O It looks like a flower.OThe symmetric flower has a

hexagon as the main flower with a square center.

OOuter petals on each side of the main flower are triangles.

OThe stem and leaves are made from triangles.

Part 1: What is Geometry?

Task2: BUILDING FROM DIRECTIONS

Create your own shape. Your partner will have to re-create it based on your verbal description of your shape

Part 1: What is Geometry?

Cooperative Learning Groups & Responsibilities

Task A Task B

Group Leader Task Manager Materials Manager

Recorder

Liaison between group and teacherGroup speaker

Ensure all members are participating, on task, and keeps track of time.

Collects and returns all materials for group

Records all information necessary on chart paper to reflect participants thoughts and ideas

Task B: Different Triangles1. Draw any triangle on your paper2. Draw a second triangle that is different in

some way from your first one. Describe in just word or two how it is different.

3. Draw a third triangle that is different from both of your other two. Describe how it is different.

4. Draw two more triangles, different from all of the ones that came before it.

5. To make “different” triangles you have to change some features of the triangle. Make a list of features of triangles that you changed.

Part 2: Triangles and Quadrilaterals

Task A: Triangle Sort1. Sort the entire collection into three

groups so that no triangle belongs to two groups.

2. Give a description or name to each of the groups and record on chart paper.

3. Once you have found one criterion for sorting. Determine a second.

Part 2: Triangles and Quadrilaterals

Task 1: Classifying TrianglesThe following shows how triangles can be classified according to some of their features: ANGLES, SIDES, SIZE

Part 2: Triangles and Quadrilaterals

OSketch a triangle in each of the nine cells.

OOf the nine cells in the chart, two of them are impossible to fill. Can you tell which ones and why?

Part 2: Triangles and Quadrilaterals