Descartes' circle theorem | Soddy's formula (englanti)
Etsi sanaa " Descartes' circle theorem " OR " Soddy's formula " NRICH | PLUS | maths.org | Googlella
Määritelmä taso 5
If we draw four circles A, B, C, D so that they do not overlap but each touches the other three, and if we call the radii of the circles r1, r2, r3, r4, and let b1=1/r1, etc, then ( b1 + b2 + b3 + b4 ) 2 = 2 ( b1 2 + b2 2 + b3 2 + b4 2 ).
Suhteet
- yleisempi:
- (en) Theorem
- viitteet:
- (en) Circle
- (en) Radius
- katso myös:
- (en) Apollonius' problem
Rahoittajat: EU Socrates Minerva, HeyMath!, Cambridge University Press