Guided Lesson: Circles - Theresa Joseph | Library

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When measuring the size of objects, you can make measurements of many dimensions.
______________  is a 1D measurement
_________   is a 2D measurement and
___________  is a 3D measurement    

Other Answer Choices:

Volume

Perimeter

Area

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Some examples of 1D units are  ________  ________  _______  
Some examples of 2D units are ________  ________  _________  
Some examples of 3D units are ________  ________  _________  

Other Answer Choices:

mm^3

km^2

km

A circle is a perfectly symmetric object. Can you guess what kind of equation creates a circle? 
(Remember the equation of a parabola was 

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Try out different equations on DESMOS and see which one makes a circle. Attach a screenshot of your trials here.

The boundary of a circle is called the circumference of a circle and the length of the circumference is given by 
Where
C - Circumference
r - Radius of the circle

You will always notice π when measuring things related to circles and it measures 3.14. 

Use the formula given to the left and the calculator given above to find the following:

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Find the circumference of a circle whose radius is 9 cm.

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Find the circumference of a circle whose diameter is 5 inches.

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Find the radius of a circle whose circumference is 200 cm.

The flat space occupied by a circle is called the area of a circle and  is given by 
Where
A - Area
r - Radius of the circle

You will always notice π when measuring things related to circles and it measures 3.14. 

Use the formula given to the left and the calculator given above to find the following:

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Find the area of a circle whose radius is 9 cm.

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Find the area of a circle whose diameter is 5 inches.

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Find the radius of a circle whose area is 360 m^2.

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Match each definition with a part of the circle.

Other Answer Choices:

A diameter is a chord that passes through the center of a circle.

A secant is a line that intersects a circle at two points.

A tangent is a line that touches a circle at only one point.

A chord is a line segment with its endpoints on a circle.

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Match the following definitions with the parts of the circle in the diagram.

Other Answer Choices:

The smaller arc is the minor arc.

The major segment is the larger segment.

The minor segment is the smaller segment. (‘Segment’ usually refers to the minor segment.)

The larger arc is the major arc.

Solve the following that have been marked. The rest is optional, you can do it for extra practice. 

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