(41C) Area of Triangle (SSS)
11-12-2018, 08:28 PM
Post: #10
 Dieter Senior Member Posts: 2,397 Joined: Dec 2013
RE: (41C) Area of Triangle (SSS)
(11-12-2018 02:55 PM)Albert Chan Wrote:
(11-10-2018 03:22 PM)Albert Chan Wrote:  If the sides are sorted, a >= b >= c, Kahan's formula is more accurate.
(11-12-2018 01:32 AM)Albert Chan Wrote:  Let y = (c - (a-b))*(c + (a-b)) / 4, then Area Δ = √((ab-y)*y)
...
Edit: this is the HP-12C code for above tests (order does not matter):

Both the formula and the program look good.
But is there a proof that the formula is (at least) as exact as Kahan's?
Testing some examples does not count. ;-)

Dieter
 « Next Oldest | Next Newest »

 Messages In This Thread (41C) Area of Triangle (SSS) - Gamo - 11-10-2018, 12:20 PM RE: (41C) Area of Triangle (SSS) - Albert Chan - 11-10-2018, 03:22 PM RE: (41C) Area of Triangle (SSS) - Dieter - 11-10-2018, 08:53 PM RE: (41C) Area of Triangle (SSS) - Albert Chan - 11-12-2018, 02:55 PM RE: (41C) Area of Triangle (SSS) - Dieter - 11-12-2018 08:28 PM RE: (41C) Area of Triangle (SSS) - Albert Chan - 11-12-2018, 10:33 PM RE: (41C) Area of Triangle (SSS) - Gamo - 11-11-2018, 05:04 AM RE: (41C) Area of Triangle (SSS) - Dieter - 11-11-2018, 07:53 AM RE: (41C) Area of Triangle (SSS) - Gamo - 11-11-2018, 12:23 PM RE: (41C) Area of Triangle (SSS) - Dieter - 11-11-2018, 04:25 PM RE: (41C) Area of Triangle (SSS) - Albert Chan - 11-12-2018, 01:32 AM RE: (41C) Area of Triangle (SSS) - Albert Chan - 11-16-2018, 03:33 AM RE: (41C) Area of Triangle (SSS) - Albert Chan - 12-04-2019, 03:03 PM

User(s) browsing this thread: 1 Guest(s)