Math CC7/8 – Mar. 2 Math Notebook: Things Needed Today (TNT): Pencil/Math Notebook/Calculator Filling & Wrapping 4.1-4.2 Math Notebook: Topic: Volume of Cylinder HW: pg. 82-83 #3, #4 (only do volume), #7a, #29 & worksheets

What’s Happening Today? Warm up Lesson 4.1 (short version) &4.2 Vol. of Cylinders! Begin HW?

Warm Up (no calculator!) What is the slope of the line represented by the equation What is the y-intercept of the line represented by the equation 2 3 y = x - 4 -4 2 3 y = x - 4 2/3 Solve the equations. 2. 4(w - 6) = 3(w + 1) 1. 10b + 46 = 3(b -15) 10b+ 46 = 3b-45 -3b -3b 7b + 46 = -45 -46 -46 7b = -91 7 7 b= -13 4w – 24 = 3w + 3 + 24 +24 4w = 3w +27 -3w -3w w = 27

More Warm Ups… A = π (2.5) A = π (6.25) A = 19.625 square inches A = π r * r A = π (9)(9) A = 254.34 square feet About 255 square feet 2 A = π (2.5) A = π (6.25) A = 19.625 square inches

More Warm Ups…. A = π r2 = (3.14)5(5) = 78.54 cm sq. C = 2πr Find the area of the circle and the circumference C = 2πr = 2(3.14)(5) = 31.42cm d=10cm A = π r2 = (3.14)5(5) = 78.54 cm sq.

28 cm sq 76 cm sq 3. You can use the radius and height to find the area of the circle(π x6) and to find the length of the rectangle.. 28 cm sq SA= 132 cm sq 4. You could move the circles to any other position along the long side of the rectangle as long as there is one circle on each long side.

2. SA = 5cm(4cm*3.14) + 2(3.14)(2cm)(2cm) = 87.92 cm sq

276.32 cm sq

We did not do this part of 2.1!  V = (3.14) (r) (r) (h) Skip

The cylinder with the larger base has a larger volume The cylinder with the greater height has a smaller volume.

B = (3.14) 5 x 5 What is the area of the base? (B) V = 78.5 x 12 Suppose that a cylinder has a radius of 5 cm and a height of 12 cm. B = (3.14) 5 x 5 What is the area of the base? (B) What is the volume of the cylinder? V = 78.5 x 12 = 942 cubic cm What is the formula for volume of a cylinder?

The cylinders have different areas of the base (B) and different heights, so the volumes will be different. So… if you build 2 cylinders from the same rectangle, the one with the larger base will have the greatest volume.

p. 83 #3, 4 – volume only, #7a, & worksheets Homework: F&W 4.1-4.2 p. 83 #3, 4 – volume only, #7a, & worksheets