This is a program to find the area of a triangle from the length of three sides using Heron's formula.

* about Heron's formula

* about Heron's formula

You can input Integer, fraction, and decimal. Values must be larger than 0.

Number of characters that can be input, is 7.Number of characters that can be input, is 7.

**About fraction input:**- For ex, "2/3"(two thirds) - please input "2" first, and "/", "3".
- In case of mixed number fraction - for ex "3+4/5".