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.
In December 1956 many key members of the Congress Alliance were arrested and charged with treason, including almost the entire executive committee of the ANC, as well as the SACP, the SAIC, and the COD. 105 Africans, 21 Indians, 23 whites and 7 coloured leaders were arrested.