Hi!
The measure of angle x is 60 degrees so the measure of angles 2x is 120 degrees.
We see that they are made up of identical squares, meaning that each side of each square is the same length. There are 12 square sides that make up the perimeter of A, so we can do 72/12 which is 6. We see there are ten total square lengths on the perimeter of b, so we can do 6 times 10 which is 60 cm. That’s your perimeter.
A^2 + b^2 = c^2
3^2 + 4^2 = c^2
9 + 16 = c^2
25 = c^2
5 = c
A={2,3,5}
B={1,3,4}
A∩B={3}
R: a. {3}
