Drawings and Nets Chapter 1 Section1 Geometry Mr. Miller

Isometric drawing is a way to show three sides of a figure from a corner view. You can use isometric dot paper to make an isometric drawing. This paper has diagonal rows of dots that are equally spaced in a repeating triangular pattern.

Example 2: Drawing an Isometric View of an Object Draw an isometric view of the given object. Assume there are no hidden cubes.

There are many ways to represent a three dimensional object There are many ways to represent a three dimensional object. An orthographic drawing shows three different views of an object: top, front, and right side.

Example 1 Draw all three orthographic views of the given object. Assume there are no hidden cubes.

Example 1 Continued

Figures and Drawings Make an orthographic drawing of the isometric drawing below. Orthographic drawings flatten the depth of a figure. An orthographic drawing shows three views. Because no edge of the isometric drawing is hidden in the top, front, and right views, all lines are solid.

Example 2 Draw an isometric view of the given object. Assume there are no hidden cubes.

Note: since my presentations are just one source of instruction, I will purposefully leave out or omit some material from the book to encourage study of the text. Make sure you read each lesson before I cover it. Foundation drawings

A net is a diagram of the surfaces of a three-dimensional figure that can be folded to form the three-dimensional figure. To identify a three-dimensional figure from a net, look at the number of faces and the shape of each face.

Example 2A: Identifying a Three-Dimensional Figure From a Net Describe the three-dimensional figure that can be made from the given net. The net has six congruent square faces. So the net forms a cube.

Example 2a Describe the three-dimensional figure that can be made from the given net. The net has four congruent triangular faces. So the net forms a triangular pyramid.

Example 2b Describe the three-dimensional figure that can be made from the given net. The net has two circular faces and one rectangular face. These are the bases and curved surface of a cylinder. So the net forms a cylinder.

Make an isometric drawing of the cube structure below. Example: Make an isometric drawing of the cube structure below. You will draw all the edges of the figure that you can see. Start by drawing the front face of the figure. Next, draw the back edges of the figure. Finally, fill in the right face, top faces, and left edges. Step 1: Draw the front. Step 2: Draw the back. Step 3: Complete.

Make an orthographic drawing of the isometric drawing below. Orthographic drawings flatten the depth of a figure. An orthographic drawing shows three views. Because no edge of the isometric drawing is hidden in the top, front, and right views, all lines are solid.

Create a foundation drawing for the isometric drawing below. To make a foundation drawing, use the top view of the orthographic drawing. 1-2

(continued) Because the top view is formed from 3 squares, show 3 squares in the foundation drawing. Identify the square that represents the tallest part. Write the number 2 in the back square to indicate that the back section is 2 cubes high. Write the number 1 in each of the two front squares to indicate that each front section is 1 cube high. 1-2

D and F are the right and left side faces. Is the pattern a net for a cube? If so, name two letters that will be on opposite faces. The pattern is a net because you can fold it to form a cube. Fold squares A and C up to form the back and front of the cube. Fold D up to form a side. Fold E over to form the top. Fold F down to form another side. After the net is folded to form a cube, the following pairs of letters are on opposite faces: A and C are the back and front faces. B and E are the bottom and top faces. D and F are the right and left side faces.

Homework Due Friday Sept 16 Page 7-10 #1-5, 6, 8, 9, 12, 14, and 24 thru 30