Surface Area of Cones Lesson 15. Write the surface area formula for each solid. 1. Prism 2. Cylinder...

9
Surface Area of Cones Lesson 15

Transcript of Surface Area of Cones Lesson 15. Write the surface area formula for each solid. 1. Prism 2. Cylinder...

Page 1: Surface Area of Cones Lesson 15. Write the surface area formula for each solid. 1. Prism 2. Cylinder 3. Pyramid 4. Find the surface area of each solid.

Surface Area of Cones

Lesson 15

Page 2: Surface Area of Cones Lesson 15. Write the surface area formula for each solid. 1. Prism 2. Cylinder 3. Pyramid 4. Find the surface area of each solid.

Write the surface area formula for each solid.

1. Prism

2. Cylinder

3. Pyramid

4. Find the surface area of each solid. Use 3.14 for .a. b.

2(LW + WH + LH)

2 π r h + 2 π r2

Lateral Area + Base Area

Page 3: Surface Area of Cones Lesson 15. Write the surface area formula for each solid. 1. Prism 2. Cylinder 3. Pyramid 4. Find the surface area of each solid.

Target: Calculate the surface area of cones.

Page 4: Surface Area of Cones Lesson 15. Write the surface area formula for each solid. 1. Prism 2. Cylinder 3. Pyramid 4. Find the surface area of each solid.

The lateral area (LA) of a cone is equal to one-half the circumference (C) of the

base times the slant height (l) of the cone.

LA = Cl = πrl2

1

Page 5: Surface Area of Cones Lesson 15. Write the surface area formula for each solid. 1. Prism 2. Cylinder 3. Pyramid 4. Find the surface area of each solid.

The surface area of a cone is equal to the sum of the lateral area (LA) and the

area of the base (B).

SA = LA + B

SA = πrl + πr2

Page 6: Surface Area of Cones Lesson 15. Write the surface area formula for each solid. 1. Prism 2. Cylinder 3. Pyramid 4. Find the surface area of each solid.

Jenny serves snow cones by putting flavored ice in apaper cone-shaped cup. Find the lateral area of the snowcone cup. Use 3.14 for π.

Write the formula. LA = πrl Substitute known values. LA ≈ (3.14)(8)(10) Multiply. LA ≈ 251.2

The lateral area of the snow cone cup is 251.2 square centimeters.

Page 7: Surface Area of Cones Lesson 15. Write the surface area formula for each solid. 1. Prism 2. Cylinder 3. Pyramid 4. Find the surface area of each solid.

Find the surface area of thecone. Use 3.14 for π.

Find the length of the radius. 12 ÷ 2 = 6 Find the area of the base. πr2 ≈ (3.14)(6)2 ≈ 113.04 Write the formula. SA = πrl + B Substitute values. SA ≈ (3.14)(6)(9) + (113.04) Multiply, then add. SA ≈ 169.56 + 113.04 ≈ 282. 6

The surface area is approximately 282.6 in2.

Page 8: Surface Area of Cones Lesson 15. Write the surface area formula for each solid. 1. Prism 2. Cylinder 3. Pyramid 4. Find the surface area of each solid.

1. The slant height of a cone is 4 feet. The radius of the cone is 3 feet. Use 3.14 for .

a) Find the lateral area of the cone.

b) Find the surface area of the cone.

2. The lateral area of the cone is 541.65 mm². Find the length of the radius. Use 3.14 for π.

Page 9: Surface Area of Cones Lesson 15. Write the surface area formula for each solid. 1. Prism 2. Cylinder 3. Pyramid 4. Find the surface area of each solid.

How is lateral area calculated for a prism, cylinder, pyramid and cone?

What is similar about finding the surface area of a cone and a pyramid?