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Lesson Part 2 Lesson 8 "Hemispheres of Circles"

Circles part 2 Lesson 7 Proportions and Review

Circles:Hemispheres

Circles:Proportions

High School Geometry: Proportions,Hemispheres



Define linear measurement ( radius and diameter)

Area measure explained

Volume explained

How to convert the linear relationship to an area relationship and a volume relationship

There are several examples of converting from linear to area to volume and keeping the correct ratios

Application problems on surface area and volumeA balloon has a radius of 6in. Describe what happens to the balloon’s surface area if the balloon inflates and the radius changes to 12in.

Describe what happens to the same balloon’s volume if the radius is doubled

A sphere has a radius of 4 in. What happens to the sphere’s volume if the radius is halved?

A sphere has a radius of 8in. What happens to the sphere’s surface area if the radius is halved?

Fills in radius,surface area and volume chart









 Problems in which you are given area and you need to find volume or given volume and you find area.

 A bowling ball has a diameter of 8 inches. Find its volume.

What is the approximate radius of a sphere with a surface area of square 40 pi square feet?

Find the distance traveled in one back-and-forth swing by the weight of a 12-in pendulum that swings through a 75o angle?

A quiche is sliced into 8 equal pieces. The arc length of one piece of quiche is 6.28 inches. What is the diameter of the quiche?

 Hemisphere problems

 Finding area of a hemisphere

 Finding the volume of a hemisphere

 Example 1 Given radius find volume

 Example2 Given radius find volume


Circles have many rules and theorems. This unit covers many of the important theorems of circles. There are videos for each lesson and extensive practice problems. Check the Table of Contents for a list of all of the topics covered