Draw an acute triangle

In triangle abc, the length of side ab is 12 cm, the length of side bc is 5 cm, and the length of side ca is 9 cm. find the measure of angle a using the law of cosines.

(urgent ) use pi 3.14 to estimate the circumference of the circle to the nearest hundredth middle is 4in (urgent )

A0.40 kg soccer ball is kicked so that its incoming velocity of 5 m/s is changed to an outgoing velocity of -25 m/s. what impulse does the player apply to the ball?