Lesson Overview:

 

• Arc Length

• Sector Area

• Area of Triangle

 

Part A and B: Arc Length

To find the length of arcs we use the following formulas.

It is important to remember not to get diameter and radius confused.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

These are some videos teaching how to find arc length and area of a sector

 

 

 

 

 

 

 

 

 

 

 

Example Problems:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Part C: Area of a Triangle 

To find the area of a triangle you can use a sine formula. Make sure you identify the sides and angles of the triangle appropriately. Once you have done this, all you must do is plug in the necessary variables.

 

This is the Formula

 

 

 

 

 

 

 

 

 

 

 

 

This video uses the sine formula to solve for the area of a triangle:

 

 

 

 

 

 

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Example Problems:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SAT Testing of Arc Lengths:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Real World Application

 

 

 

 

 

 

 

 

 

 

Conclusion:

You can use the formulas for the length of sectors and area of sectors to solve for sectors of a circle. Make sure you appropriately identify the angles and radius you will be using to solve for these. Secondly, you can also use the formula for solving for the area of traingle only having two know two sides and one include angle.