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.
U.S. anti-Communist propaganda of the 1950s, specifically addressing the entertainment industry. McCarthyism is the practice of making accusations of subversion or treason without proper regard for evidence.