Can someone find the answers for these 2 problems using distance formula?? thx to whoever does

Abcd is a square. what is the measure of angle bac

Abag contains 3 red marbles, 2 blue marbles, and 2 green marbles. one marble is picked, then another marble. assume that the selections are made with replacement. a) find the probability of picking two red marbles with replacement. b) find the probability of picking a red marble and a blue marble. assume the selections are made without replacement. c) find the probability of picking two red marbles without replacement. d) find the probability of picking a red marble and a blue marble without replacement.

The value of the expression 16-^3/4 8 1/8 -6 6 1/40 1/64