Area of Triangles

Area of Triangles

CCSS.Math.Content.7.G.B.6

Solve real-world and mathematical problems involving area, volume and surface area of two- and three-dimensional objects composed of triangles, quadrilaterals, polygons, cubes, and right prisms.

Poll

Rate your understanding of finding the Area of Triangles:

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  Know how to find the area of a triangle

• Good !

  
  

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  I have NOT seen lessons on how to find the area of a triangle, and need to learn how.

Find area of the shaded shape.

Aaron was plotting the shape of his flower garden. While it was an irregular shape, it was perfect for his yard.

What is the area of his flower garden ? (All measurements are in feet.

What is a triangle

• A two-dimensional polygon with three edges and three vertices.

• It is one of the basic shapes in geometry.

• The sum of the internal angles equal 180^o.

Finding the Area of a Triangle

Alejandra's mom is moving her company to a new office space. Her old office space was 302 square meters (m²).

How much bigger is the office space of her new office (shown) than her old office space?

Finding the Area of a Triangle

Given:

the base = 30 and the height = 21

Find:

area of the triangle

Area_Δ = 1/2 * b * h

Area_Δ = 1/2 * 30 * 21 = 315 m²

Finding the Area of a Triangle

• If Alejandra mom's old office space was 302 m². How much bigger is the new office (shown) than her old office space?

• 315 m² - 302 m² = 13 m²

Finding the Area of a Triangle

1) Identify what has been given and what you are looking to find.

Given: b = 30 km and h = 20 km

2) Write down the formula.

A_Δ = 1/2 x b x h

3) Solve (using calculator if needed)

A_Δ = 1/2 x 30km x 20km = 300 km²

Finding the Area of a Triangle

1) Identify what has been given and what you are looking to find.

Given: b = _____ and h = _____

2) Write down the formula.

A_Δ =

3) Solve (using calculator if needed)

A_Δ =

Area of a Triangle - UR Turn

1) Identify what has been given and what you are looking to find.

Given: b = _____ and h = _____

2) Write down the formula.

A_Δ =

3) Solve (using calculator if needed)

A_Δ =

Area of a Triangle - UR Turn

Find the area of triangle A

A_Δ =

Find the area of triangle B

A_Δ =

WHAT did you get ?

Answers in the CHAT ! ! !

Finding the Area of a Triangle

Find the area of triangle A

A_Δ = 1/2 x b x h = 1/2 x 6 x 7 = 21 cm²

Find the area of triangle B

A_Δ = 1/2 x b x h = 1/2 x 4 x 7 = 14 cm²

Poll

Rate your understanding of finding the Area of Triangles:

• Expert !

  
  

  Know how to find the area of a triangle

• Good !

  
  

  I understand how to find the area of a triangle, but need more practice.

• Poor!

  
  

  I don't understand how to find the area of a triangle and need assistance during your office hours.