The sum of the three inside angles of a triangle need to equal 180 degrees.
X = 180 - 79 - 70
x = 31 degrees.
180-110=70. Y is 70 degrees. 360n-180 gives the angles of any polygon, take the angles inside of the polygon and subtract them from 1630 for your answer for z.
There are 20 skirts in total and five of them are yellow.
The probability that she will pick a yellow skirt is 5/20 (simplifies to 1/4)
Multiply this by the probability that the coin will land on tails 1/2
1/4 x 1/2 =
1/8
Maria has a 1/8 chance that she will pick a yellow skirt AND land the coin on tails.