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.
Joseph McCarthy created a thing called McCarthyism which is the practice of publicizing accusations of political disloyalty with insufficient regard to evidence. It is mostly associated with the red scare. There was an increase in communism influence on the Espionage by the Soviets. During McCarthyism most Americans were accused of being communists but actually weren't. Through 1950 and 1954 Joseph McCarthy developed a personal and political approach in becoming Senator of the United States. He practiced politically accusing someone.