The reason is the gotter of the right angle is 12
Quadrilateral ABCD is a kite
AB is congruent to AD -- definition of a kite
BC is congruent to DC -- definition of a kite
draw a line segment AC
AC is congruent to itself -- identity
triangle ABC is congruent to triangle ADC -- SSS
angle ABC is congruent to ADC
QED
For the first question, all you need to know is that the (amount you want) divided by (the amount of cards total) is the probability of getting the amount you want at random. for example, if there are 3 red marbles in a bag of ten marbles, you divide 3 by 10 (0.30) the probability of picking up a red marble is 30%. try adding up how many cards you want to pick up by the number of cards total.
Greatest Common Factor: 12-1/3 = -4/12, 7/4 = 21/12-4/12 + 21/12 = 17/12
Answer in simplest form: 17/12