# Fractional Lengths in Triangles and Prisms

Warmup

Activity #1

Find Area of a Triangle with Fractional Lengths & Missing Side Lengths.

• Study the diagrams below and answer the questions that follow.

Find the area of Triangle A in square centimeters. Show your reasoning.

The area of Triangle B is 8 square units. Find the length of b. Show your reasoning.

The area of Triangle C is 54/5 square units. What is the length of h? Show your reasoning.

Activity #2

Finding Missing Sides Lengths of Similar Triangles with Decimal Lengths.

(1.) How many cubes with edge lengths of  inch are needed to fill the cube below?

(2.) What is the volume in cubic inches, of a cube with edge lengths of   inch? Explain or show your reasoning.

Activity #3

Find Volume of a Prism by Counting Cubes.

(1.) Four cubes are piled in a single stack to make a prism. Each cube has an edge length of Â½ inch. Sketch the prism, and find its volume in cubic inches.

(2.) For each prism, record in the table how many -inch cubes can be packed into the prism.

Challenge #1

The area of Triangle B is 8 square units. Find the length of b. Show your reasoning.

Challenge #2

Challenge #3

Which expression can be used to find how many cubes with edge length of 13 unit fit in a prism that is 5 units by 5 units by 8 units?

Quiz Time