1. LESSON Today: Go over Part 1 12.1 Instruction We are what we repeatedly do. Excellence, then, is not an act, but a habit. Aristotle

2. LESSON 12.1 Representations of 3-Dimensional Figures Objective: 1.Draw isometric views of three-dimensional figures. 2.Investigate cross sections of three- dimensional figures. Vocabulary: isometric view, cross section

3. LESSON isometric view – corner views of three-dimensional objects on two-dimensional paper cross section – the intersections of a solid and a plane

4. LESSON Use isometric dot paper to sketch a triangular prism 6 units high, with bases that are right triangles with legs 6 units and 4 units long.

5. LESSON Use isometric dot paper and the orthographic drawing to sketch a solid.

6. LESSON Use isometric dot paper and the orthographic drawing to sketch a solid.

7. LESSON Use isometric dot paper and the orthographic drawing to sketch a solid.

8. LESSON Use isometric dot paper and the orthographic drawing to sketch a solid.

9. LESSON Example 2 Which diagram is the correct corner view of the figure given the orthographic drawing? A.B. C.D. top view left view front view right view

10. LESSON Example 3 BAKERY A customer ordered a two-layer sheet cake. Determine the shape of each cross section of the cake below.

11. LESSON Example 3 A.Cut the cone parallel to the base. B.Cut the cone perpendicular to the base through the vertex of the cone. C.Cut the cone perpendicular to the base, but not through the vertex. D.Cut the cone at an angle to the base. A solid cone is going to be sliced so that the resulting flat portion can be dipped in paint and used to make prints of different shapes. How should the cone be sliced to make prints in the shape of a triangle?

12. LESSON Example 3 What different plane figures can you make with a cross section of a pyramid? Triangle? Square? Circle? Trapezoid? Parallelogram? Kite? ?

13. LESSON Assignment Due tomorrow: 12.1 P. 841 #9-35 odd, 38