12-96th grade math

Volume of Rectangular Prisms

Objective

• To find the volume of rectangular prisms

• Why? To know how to use formulas and evaluate variable expressions using the order of operations. To further your knowledge of geometry and measurement.

California State Standards MG 1.3: Know and use … the formula for the

volume of a rectangular solid.AF 3.1: Use variables in expressions describing

geometric quantities AF 3.2: Express in symbolic form simple

relationships arising from geometry.MR 1.3: Determine when and how to break a

problem into simpler parts.MR 2.2: Apply strategies and results from simpler

problems to more complex problems.

Vocabulary• Rectangular prism– A prism whose base is a rectangle

• Volume of a solid (A prism)– The number of unit cubes it will fit into a space

figure– Filling the solid

How to Find the Volume of Rectangles

1) Observe or draw the figure. Be sure all measurements are in equal labels.

2) Write out the formula: B x h (B = l x w) or l x w x h

3) Check work and add label³ to answer.

Pit dimensions: base = 12 ft. x 7 ft. height = 2 ft

12 x 7 x 2 = 168 ft³

Find volume of rectangular prism:

l = 5 ¾ , w = 2 ¼ , h = 1 ⅓

5 ¾ x 2 ¼ x 1 ⅓= 23 x 9 x 4 4 4 3

9 x 4 = 34 3 1

3 X 23 = 691 4 4

= 17 ¼ in³

Try It!

Find the volume1) 5 ft, 8 ½ ft, 2 ft

2) ½ in, 8 in, 10 in

3) 2 ft, 2 ½ ft, 7 ft

4) 2 ft, 1 ½ ft, 6 in for 8 bags

1) 5 x 8.5 x 2 = 85 ft³

2) 0.5 x 8 x 10 = 40 in³

3) 2 x 2.5 x 7 35 ft³

4) (2 x 1.5 x 0.5) x 8= (1.5) x 8= 12 ft³

Objective Review • To find the volume of

rectangular prisms

• Why? You now know how to use formulas and evaluate variable expressions using the order of operations. You have furthered your knowledge of geometry and measurement.

• The volume of any rectangular prism is the product of its length, width, and height, or V=lwh

Independent Practice

• Complete problems 6-12

• Copy original problem first.

• Show all work!

• If time, complete Mixed Review: 13-22

• If still more time, work on Accelerated Math.