## Wednesday, March 22, 2017

### HP 15C: Regular Polygon: Internal Angle, Area, Perimeter

Hope you all like the new background and style changes!  Thank you for the success of this blog - less than a month to the blog's sixth birthday (4/11/2017).

HP 15C:  Regular Polygon: Internal Angle, Area, Perimeter

Inputs (Store values before running the program):
R0:  n, number of sides
R1:  s, length of each side

Outputs:
R2:  θ, Internal Angle
R3:  A, Area
R4:  P, Perimeter

Formulas Used (Degrees Mode Used):

Internal Angle:  θ = 180° - 360°/n
Area:  A = (s^2 * n)/(4 * tan (180°/n))
Perimeter:  P = s * n

 Step Key Code 001 LBL C 42, 21, 13 002 DEG 43, 7 003 1 1 004 8 8 005 0 0 006 ENTER 36 007 ENTER 36 008 2 2 009 * 20 010 RCL÷ 0 45, 10, 0 011 - 30 012 STO 2 44, 2 013 R/S 31 014 RCL 1 45, 1 015 X^2 43, 11 016 RCL* 0 45, 20, 0 017 1 1 018 8 8 019 0 0 020 RCL÷ 0 45, 10, 0 021 TAN 25 022 4 4 023 * 20 024 ÷ 10 025 STO 3 44, 3 026 R/S 31 027 RCL 0 45, 0 028 RCL* 1 45, 20, 1 029 STO 4 44, 4 030 RTN 43, 32

Example:  R0 = n = 5, R1 = s = 4.  Output:  θ = 108°, A ≈ 27.5276, P = 20

This blog is property of Edward Shore,  2017.

### Carnival of Mathematics # 216

Carnival of Mathematics # 216 Welcome to a special edition of Eddie's Math and Calculator Blog.  I am once again happy to host the Carni...