# Lesson 17

Building Prisms

### Lesson Narrative

This lesson is optional. In this culminating lesson, students use what they have learned in this unit to build a triangular prism, given some measures for the angles and sides of the triangular base. There are 4 possible solutions.

This lesson is organized into three activities. First, students draw triangles that could be the base of the prism, given the conditions. They select one of the 4 possible solutions and calculate its area. Then, students create and assemble a net for the prism. They calculate its volume and surface area. In the last activity, students experiment with different ways two prisms could be put together to make one larger prism. They analyze how different configurations affect the volume and surface area of the composed prism.

### Learning Goals

Teacher Facing

• Compare and contrast (orally) triangular prisms, including comparisons of their height, cross sections, surface area, and volume.
• Compose two triangular prisms into a new prism, and describe (orally and in writing) the composite shape.
• Draw and assemble a net of a triangular prism, given two side lengths of the prism’s base and one angle measure.

### Student Facing

Let’s build a triangular prism from scratch.

### Required Preparation

Print a copy of the blackline master for each student. Rulers should be part of the geometry toolkit, but make sure that rulers provided have markings in centimeters.

### Student Facing

• I can build a triangular prism from scratch.

Building On