Essential Question: What are the different methods to find the area of a triangle and when do you use each?Demonstrated in writing in summary at conclusion of notes

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Area of a TriangleEssential Question: What are the different methods to find the area of a triangle and when do you use each?Demonstrated in writing in summary at conclusion of

notes

Essential Question: What are the different methods to find the area of a triangle and when do you use each?Demonstrated in writing in summary at conclusion of notes

Formula for area of a triangle: Area = 1/2 ·b·h

** In order to use this formula you must know the base and the height of the triangle.

Essential Question: What are the different methods to find the area of a triangle and when do you use each?Demonstrated in writing in summary at conclusion of notes

Example: Determine the area of the triangle.

Essential Question: What are the different methods to find the area of a triangle and when do you use each?Demonstrated in writing in summary at conclusion of notes

Another formula for area of a triangle is: Area = ½ ·a · b · sin C

** You can use this formula if you know two side lengths and the measure of their included angle.

Essential Question: What are the different methods to find the area of a triangle and when do you use each?Demonstrated in writing in summary at conclusion of notes

Prove that the area of a triangle is ½∙a∙b∙sinCGiven: and area of a triangle= ½∙ b∙hProve: Area = ½∙a∙b∙sinCStatement Reason

1. 1.

2. 2.

3. sinC = 3.

4. a sinC=h∙ 4.

5. 5. Substitution

6. 6. Commutative Property For Multiplication

𝑩𝑫⊥ 𝑨𝑪Area = ½ b h∙ ∙

Given

Givenha

Definition of Sine

Multiplication Property of Equality

Area = 1/2·b·a·sinC

Area = 1/2·a·b·sinC

Essential Question: What are the different methods to find the area of a triangle and when do you use each?Demonstrated in writing in summary at conclusion of notes

Example: Determine the area of the following triangles.

1. 3.

Essential Question: What are the different methods to find the area of a triangle and when do you use each?Demonstrated in writing in summary at conclusion of notes

Example: Determine the area of the following triangles.

5. 2.

Essential Question: What are the different methods to find the area of a triangle and when do you use each?Demonstrated in writing in summary at conclusion of notes

Example: Determine the area of the following triangles.

4. 6.

Essential Question: What are the different methods to find the area of a triangle and when do you use each?Demonstrated in writing in summary at conclusion of notes

Example: Determine the area of the following triangles.

7. 8.

Essential Question: What are the different methods to find the area of a triangle and when do you use each?Demonstrated in writing in summary at conclusion of notes

Homework:• Add summary to notes that answers the essential

question: “What are the different methods to find the area of a triangle and when do you use each?

• Area of a triangle worksheet