17-16 Applications
8317APPS.DOC TI-83 international English Bob Fedorisko Revised: 02/19/01 1:00 PM Printed: 02/19/01 1:39 PM
Page 16 of 20
Use the equation solver to store a formula for the area of a
regular N-sided polygon, and then solve for each variable,
given the other variables. Explore the fact that the limiting
case is the area of a circle, pr2.
Consider the formula A = NB2 sin(pàN) cos(pàN) for the
area of a regular polygon with N sides of equal length and
B distance from the center to a vertex.
N = 4 sides N = 8 sides N = 12 sides
1. Press 0 to select 0:Solver from the MATH menu.
Either the equation editor or the interactive solver
editor is displayed. If the interactive solver editor is
displayed, press } to display the equation editor.
2. Enter the formula as 0=ANNB2sin(p / N)cos(p / N), and
then press Í. The interactive solver editor is
displayed.
3. Enter N=4 and B=6 to find the area (A) of a square with
a distance (B) from center to vertex of 6 centimeters.
4. Press } } to move the cursor onto A, and then press
ƒ [SOLVE]. The solution for A is displayed on the
interactive solver editor.
5. Now solve for B for a given area with various number of
sides. Enter A=200 and N=6. To find the distance B,
move the cursor onto B, and then press ƒ [SOLVE].
6. Enter N=8. To find the distance B, move the cursor onto
B, and then press ƒ [SOLVE]. Find B for N=9, and
then for N=10.
Computing Areas of Regular N-Sided PolygonsProblem
Procedure