Topic 15 Lesson 10 Problem Solving Use Reasoning

Develop the Concept Overview In this activity, we will identify attributes that define different plane shapes and solid figures. Focus How do you know the name of a plane shape or solid figure? Materials Building Materials modeling clay pipe cleaners © 2009 abcteach. com

Engage Set the Purpose You have learned about the attributes of plane shapes and solid figures. Today, you will identify which attributes are always true about certain shapes and which are not always true. Connect What do you know about a square? What do you know about a triangle? What do you know about a cube? © 2009 abcteach. com

Model Pose the Problem Page 507 Put an X on all of the objects in the picture that look like a circle. Instruct in Small Steps How did you know which shapes were circles? Did the color of the shape help tell you it was a circle? Did the size of a shape help tell you it was a circle? The color and size of a shape do not help to tell you what a shape is because two or more of the same shape, such as these three circles, can be different colors and different sizes. To find the circles, you look for shapes that have 0 vertices and 0 straight sides. Now draw a circle around the words that are true about all circles. © 2009 abcteach. com

Small-Group Instruction Cylinders #2 The glue stick is a cylinder shape but it has its 2 flat surfaces at each end. The position of a shape does not help to tell you what shape it is. The glue stick can still be said to be a cylinder even though it is in a different position to the other two. It still has 2 flat surfaces and 0 vertices. When both items are complete, use your building materials to build shapes with given attributes, such as 3 straight sides. Size, color, and orientation are not always true of shapes. Straight sides, flat surfaces, vertices, are always true. © 2009 abcteach. com