The right triangle has one 90 degree angle and two acute (< 90 degree) angles. Since the sum of the angles of a triangle is always 180 degrees... y + z = 90 degrees. The two sides of the triangle that are by the right angle are called the legs... and the side opposite of the right angle is called the hypotenuse.
They were called the Hollywood 10 and accused of being communist. I don't think you would find many people who can name them all.
The case against the Rosenbergs was circumstantial at best. At the beginning of the trial, the prosecution announced that it would call more than 100 witnesses, including prominent scientists, who would prove that Ethel and Julius Rosenberg were part of a plot to steal secrets for the Soviet Union. In the end, only 23 were actually called forward to testify.