Alice e a lei dos cossenos

Synopsis: Alice dreams of the young Mr. Joshua, which shows in the law of cosines in an entertaining way. In the dream also appears a singer who helps Joshua in the statement with a beautiful melody. Alice awakens to find understood the demonstration of the law of cosines.
Source: Unicamp - M3, Mathematics Multimedia.
URL: http://m3.ime.unicamp.br/recursos/1047