Heron - Casio fx-7400G Programing Manual

Programming your calculator

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.
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