Programming your calculator
2
HERON
Purpose
Uses the lengths of the three sides of a triangle to calculate the area of any triangle,
using Heron's formula, known since ancient times.
Operation
Enter the length of each side, followed by . Both numbers and expressions (such as
√2) are permitted.
The program displays the area of the triangle.
Press to enter the side lengths of another triangle.
Test the program by entering sides of a familiar triangle, such as a 3-4-5 triangle, and
checking that the calculated area is correct.
Notice what happens when the program is run with side lengths that do not form a
triangle (such as 3-4-11).
There is a discussion of the use of this sort of program in the text:
Kissane, Barry & Harradine, Anthony (2000) Mathematical Interactions: Measurement,
Chatswood, NSW: Shriro, pp 19-20.
