1. Volume of a Rectangular Prism A rectangular prism is 10cm long, 5 cm wide and 6cm high. 6cm 5cm 10cm The length is 10cm or one row of 10 cubes The width is 5cm or five rows of 10 cubes making 1 layer of 50 cubes. The height is 6cm. Six layers of 50 cubes make a volume of 300 cubes. The Volume is 50cm² x 6cm = 300cm 3 So…. Volume = Number of cubes in each layer x number of layers *The number of cubes in each layer is the area of the base of the prism. It is the length times the width. The number of layers in the prism is its height SO….

2. Volume of a Rectangular Prism It is not always practical to count centimetre cubes to find the volume We can develop a formula to help us calculate the volume of a rectangular prism. For example:

3. Lesson #9 Volume of a Rectangular Prism Volume = Base area x Height Another way to write the formula is: Volume= Length x Width x Height V = l x w x h Question: Find the volume of a rectangular prism 10.5cm long, 4.2 cm wide and 5.0cm high. Volume= L x W x H = 10.5cm x 4.2cm x 5.0cm = 220.5cm 3

4. Lesson #9 Volume of a Rectangular Prism PRACTICE  page 237 Please try # 1,3 and 5

5. Lesson #9 Volume of a Rectangular Prism PRACTICE  page 237 Please try # 1,3 and 5 1. a. V = l x w x h = 5cm x 2 cm x 6cm = 60cm 3 b. v = l x w x h = 7cm x 3cm x 2cm = 42cm 3

6. Lesson #9 Volume of a Rectangular Prism PRACTICE  page 237 Please try # 1,3 and 5 C. V= l x w x h = 15cm x 4cm x 3cm = 180cm 3

7. Lesson #9 Volume of a Rectangular Prism 3) Dog Box Volume: v = l x w x h = 117cm x 97cm x 61cm = 692 289 cm 3 Dog Compartment Volume: v = l x w x h = 38cm x 97cm x 46cm = 169 556 cm 3 a)The volume of each dog compartment is 169 556 cm 3. b)3 dog compartments = 3 X 169 556 = 508 668 cm 3. So, the volume not used is 692 289 - 508 668 = 183 621 cm 3.

8. Lesson #9 Volume of a Rectangular Prism 5. What is the height? v = l x w x h 90cm 3 = l x w x h where l = 9cm and w = 5cm 90cm 3 = 45cm ² x h h = 2cm Since 90 ÷ 45 = 2, the height of the prism is 2cm.