 Soki bapesi yo ba points misato A, B na C, sala calcul ya angle ABC.
Tokoki kosalela mobeko ya cosine mpo na koluka angle. Soki bapesi ba points misato A, B na C, angle ABC ekoki ko calculer boye : Ya liboso tozui ba distances entre ba points : AB = sqrt((3 - 1)^2 + (4 - 2)^2) = sqrt( 8) BC = sqrt ((5 - 3) ^ 2 + (6 - 4) ^ 2) = sqrt (8) AC = sqrt ((5 - 1) ^ 2 + (6 - 2) ^ 2) = sqrt( 32) Na kosalelaka ba distances oyo tokoki koluka cosene ya angle ABC na kosalelaka loi ya cosene : cos(ABC) = (AB^2 + BC^2 - AC^2)/(2 * AB * BC) cos(ABC) = (8 + 8 - 32)/(2 * sqrt(8) * sqrt(8)) cos(ABC) = -0.5 Donc angle ABC ezali arccos(-0.5) radians to 120 degrés.