Geometry and Area Formulas, help.?

Parallelogram: A=bh
Triangle: A=1/2 bh
Trapezoid: A=1/2(b1+b2)h

The area formula for a rectangle is A=bh. Explain thoroughly how the three formulas are derived from the area formula from a rectangle.

the area of a rectangle is A = bh, the base time the height.
The Parallelogram is the same as the Rectangle, as a Parallelogram is a rectangle with part chopped off one side and added onto the other…

A triangle is half of a rectangle. (Right Angle triangles are just rectangles, or squares, cut in half. With other triangles, if you draw a tight rectangle around it, the area outside of the traiangle will be the same as the area of the triangle.

With the Trapezoid, again you can cut off a bit, twist it around and add it to the other side and it will become a rectangle. the height of the rectangle will be the same as the Trapezoid, but the base would be the average of b1 and b2, so therefore 1/2(b1 + b2).. so multiply that by the height to get the area.

2 Responses to “Geometry and Area Formulas, help.?”

  1. the formula for the rectangle parallelogram and a square is the same.
    2 same triangles theoretical will be the same as a rectangle.
    not sure abt the trapezoid
    References :

  2. the area of a rectangle is A = bh, the base time the height.
    The Parallelogram is the same as the Rectangle, as a Parallelogram is a rectangle with part chopped off one side and added onto the other…

    A triangle is half of a rectangle. (Right Angle triangles are just rectangles, or squares, cut in half. With other triangles, if you draw a tight rectangle around it, the area outside of the traiangle will be the same as the area of the triangle.

    With the Trapezoid, again you can cut off a bit, twist it around and add it to the other side and it will become a rectangle. the height of the rectangle will be the same as the Trapezoid, but the base would be the average of b1 and b2, so therefore 1/2(b1 + b2).. so multiply that by the height to get the area.
    References :

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