en.wikipedia.org/wiki/Heron%27s_formula

In geometry, Heron's **formula** (sometimes called Hero's **formula**), named after
Hero of Alexandria, gives the **area** of a triangle by requiring no arbitrary choice of
side as base or vertex as origin, contrary to other **formulas for the area** of a
triangle, .... The **formula** is credited to Heron (or Hero) of Alexandria, and a **proof**
can be ...

www.basic-mathematics.com/proof-of-the-area-of-a-trapezoid.html

Find here a nifty **proof** of the **area of a trapezoid** using some basic math concepts.

www.mathopenref.com/trapezoidareaderive.html

This page describes **how to derive** the forumula for the **area of a trapezoid**, by
creating a parallelogram from two congruent trapezoids. The **equation** is then ...

illuminations.nctm.org/Lesson.aspx?id=1893

The main portion of this lesson involves the **derivation** of an **area formula** for
**trapezoids**. Prior to that, allow students some exploration time. Ask them to
suggest ...

mathforum.org/library/drmath/view/55006.html

Date: 04/11/98 at 09:29:50 From: Dwight Subject: Trapezoid area **formula proof**
We were told that the **area of a trapezoid** is half the sum of the parallel sides x the
...

math.stackexchange.com/questions/277025/trapezoid-area-proof-by-dividing-it-into-two-triangles

Jan 13, 2013 **...** When you divides the **trapezoid** in two triangles, the **area** of the .... years ago, we
had to **prove** the **trapezoid area formula** in two different ways.

solvemymaths.com/2015/03/07/proof-area-of-a-trapezium-trapezoid-us

Mar 7, 2015 **...** At the Don Steward event last weekend, Don demonstrated how the **formula** for a
**trapezium** can be derived in different ways. He asked the ...

www.khanacademy.org/math/basic-geo/basic-geo-area-and-perimeter/area-trap-composite/v/area-of-a-trapezoid-1

**Area of a trapezoid** is found with the **formula**, A=(a+b)/2 x h. Learn how to use the
**formula** to find area of trapezoids.