# How do you use Heron's formula to find the area of a triangle with sides of lengths #12 #, #5 #, and #7 #?

##### 1 Answer

Jan 21, 2016

The given numbers cannot be lengths of sides of a triangle. (The area is zero)

#### Explanation:

The Heron's formula says that for any triangle with sides

If we substitute given numbers we see, that:

You should have noticed, that given numbers cannot be the lengths of sides of a triangle, because **smaller** then the sum of remaining sides