**Math Textbook Pages 185-186. Show you knows and Questions 1,3,5.**

**Show you know #1:**

**Calculate the surface area of a cylindrical waste bucket without a lid that measures 28 cm high and 18 cm**

**in diameter. Give your answer to the nearest square centimeter.**

**Answer:**

TSA= (2π.r.r) + (2.r.π.h)

TSA= (2x3.14x9x9) + (2x9x3.14x28)

TSA= 508.68 + 1582.56

TSA= 2091.24cm²

**Show you know #2:**

**Calculate the surface area of this cylinder to the nearest tenth of a square centimeter.**

**Diameter: 9 cm**

Height: 55 cm

Answer:

TSA= (2π.r.r) + (2.r.π.h)

Height: 55 cm

Answer:

TSA= (2x3.14x4.5x4.5) + (2x4.5x3.14x55)

TSA= 127.17 + 1554.3

TSA= 1681.47cm²

**1. What are the similarities and differences between finding the surface area of a prism and**

**finding the surface area of a cylinder?**

**Answer:**

Differences: The surface area of a prism is that it is rectangular. It has 6 faces. A cylinder has a total of three surfaces: a top, bottom, and middle. The top and bottom, which are circles.

Similarities: They both have nets to identify the answer. They are also easy to visualize.

**3. a) Draw a net for this cylinder.**

b) Sketch a different net for this cylinder.

b) Sketch a different net for this cylinder.

**5.**

**Find the surface area of each object to the nearest tenth of a square unit.**

a) Diameter: 2.5 cm

a) Diameter: 2.5 cm

**Circumference: 16 cm**

b)Diameter: 0.003 m

Circumference: 16 m

b)Diameter: 0.003 m

Circumference: 16 m

**Answer:**

**a)**

TSA= (2π.r.r) + (2.r.π.h)

TSA= (2x3.14x1.25x1.25) + (2x1.25x3.14x16)

TSA= 9.8125 + 125.6

TSA= 135.4cm²

**b)**

TSA= (2π.r.r) + (2.r.π.h)

TSA= (2x3.14x0.0015x0.0015) + (2x0.0015x3.14x16)

TSA=0.00001413 + 0.15072

TSA= 0.2cm²

**Click HERE to learn more about Cylinders.**

Cylinder Volume and Volume Problems

**Jumbo**

v= π.r.r.h

v= (3.14x10x10) x 40

v= 314 x 40

v= 12560cm3

**Popcorn Lover's**

v= π.r.r.h

v= (3.14x15x15) x 20

v= 706.5 x 20

v= 14130cm3

Martha should buy the container that says "Popcorn Lover's" if she wants more popcorn for her money.

**Outside**

r=d/2

r=1/2

r=0.5

v= π.r.r.h

v= (3.14x0.5x0.5x10)

v= (0.785m2) x 10m

v= 7.85m3

**Inside**

v= π.r.r.h

v= (3.14x0.4x0.4x10)

v= (0.5024m2) x 10m

v= 5.024m3

7.85cm3 - 5.024m3 = 2.862 or 2.9m3

The volume of the concrete required to make the culvert is 2.9m3.

Great post Raelynn. Your post looks very neat and i like the pictures. I liked that you bolded the questions to make it stand out. Great job.

ReplyDeleteGood job! I really liked your pictures and the video really helps!

ReplyDeleteGreat post Raelynn. I liked that your post is very neat, organized and well explained. Next time you should stick with less colors.

ReplyDeleteNice post Raelynn! Your scribe looks organized and neat.

ReplyDelete