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Hero's and Brahmagupta's Theorems  Lesson 118
Today we learned two formulas that were developed 20003000 years ago. The first was discovered by Hero of Alexandria and is therefore called Hero's Formula. It helps us to find the area of a triangle given the lengths of its three sides:
An example of using this to find the area of a triangle follows:
Simply apply the formula! First, you need to find the semiperimeter and then you can solve for the area.
The second formula was developed by a Hindu mathematician named Brahmagupta. His formula allows us to find the area of cyclic quadrilaterals:
Here's an example problem:
Again, start by finding the semiperimeter and then just use the formula:
