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+--- Thread: (20S and 21S) Triangle Program (/thread-8452.html)
(20S and 21S) Triangle Program - Eddie W. Shore - 06-03-2017 06:29 PM
Given three Cartesian coordinates, through points (R1, R4), (R2, R5), and (R3, R6), this program calculates:
1. The lengths of each side, represented by R7, R8, and R9.
2. The angle between lines connected by (R1, R4)-(R2, R5) and (R2, R5)-(R3, R6). The angle is stored in R0.
3. The area of the triangle. This is the final results shown.
[see diagram below]
The keystrokes for the HP 20S and HP 21S in this program are the same. Store the coordinates in variables R1 through R6, then press XEQ A.
HP 20S and HP 21S Program: Triangle Program
Code:
STEP CODE KEY
01 61, 41, A LBL A
02 22, 1 RCL 1
03 65 -
04 22, 2 RCL 2
05 31 INPUT
06 22, 4 RCL 4
07 65 -
08 22, 5 RCL 5
09 51, 21 >P
10 51, 31 SWAP
12 26 R/S
13 71 [ C ] Clear
14 22, 2 RCL 2
15 65 -
16 22, 3 RCL 3
17 31 INPUT
18 22, 5 RCL 5
19 65 -
20 22, 6 RCL 6
21 51, 21 >P
22 51, 31 SWAP
23 21, 8 STO 8
24 26 R/S
25 71 [ C ] (Clear)
26 22, 1 RCL 1
27 65 -
28 22, 3 RCL 3
29 31 INPUT
30 22, 4 RCL 4
31 65 -
32 22, 6 RCL 6
33 51, 21 >P
34 51, 31 SWAP
35 21, 9 STO 9
36 26 R/S
37 71 [ C ] Clear
38 22, 8 RCL 8
39 51, 11 x^2
40 75 +
41 22, 9 RCL 9
42 51, 11 x^2
43 65 -
44 22, 7 RCL 7
45 51, 11 x^2
46 74 =
47 45 ÷
48 2 2
49 45 ÷
50 22, 8 RCL 8
51 45 ÷
52 22, 9 RCL 9
53 74 =
54 51, 24 ACOS
55 21, 0 STO 0
56 26 R/S
57 23 SIN
58 55 *
59 22, 7 RCL 7
60 55 *
61 22, 8 RCL 8
62 45 ÷
63 2 2
64 74 =
65 61, 26 RTNExample:
Inputs:
(R1, R4) = (4, 8)
(R2, R5) = (2, 3)
(R3, R6) = (3, 10)
Outputs:
R7 = 5.3852
R8 = 7.0711
R9 = 2.2361
R0 = 34.6952°
Area = 10.8374