Select the angle that correctly completes the law of cosines for this triangle 24^2+25^2-2(24)(25)cos =7^2 a) 180 degrees b) 90 degrees c) 74 degrees d) 16 degrees

D 16 degrees.

and you can use calculator to calculate. but I think, it's multiple choice question so you can use directly the choices, if the answer is right, just choose it.

Answer d; a supplementary angle = 180°, so if that angle = 150°, y would = 30°.