1. Lateral Area & Surface Area Of Cylinders
Geometry 10:2

2. Notes
Using the Word Bank, label the parts of the net for a right cylinder.

3. Notes: LATERAL AREA
In a cylinder, the lateral area is the lateral or side surface of the solid but it is the shape of a rectangle in the net.

4. Notes: Total Surface Area
The total surface area of a cylinder will include the lateral surface (the rectangle in the net) and the two bases which are in the shape of a circle.

5. Example: Lateral Area: 2πrh 2×π×3 = 6π ≈ 18.8495 6π × 7 =42π ≈ 131.9
Total Surface Area: 2πrh + 2(πr²)
42π + 2(π3²) = 60π ≈ 180.5

6. Example: Lateral Area: 2πrh
The radius is 7 since both legs are the radius of the circle.
14π ≈ 43.98
14π × 5 = 70π ≈ ft²
Total Surface Area: 2πrh + 2(πr²)
70π + 7²π = 70π + 49π = 119π
≈373.8 ft²

7. Example: Lateral Area: 2πrh
Since the hypotenuse is 10 then the radius is 52
102 π × 4 ≈ 44.4 × 4 ≈ 177.7
Total Surface Area: 2πrh + 2(πr²)
402 π + 2∙π(52)²
402 π + 2(50π) ≈ 491.9cm²

8. Example: Lateral Area: P∙h 8 × 6 × 11 = 528 in²
Total Surface Area: P∙h + B
(360÷6÷2) = 30
4 ÷ tan(30) = 6.9
Area of this hexagon is × 2 = 332.6
= 860.6