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 two met in 1951, while Reagan was serving as president of the Screen Actors Guild (SAG) and Nancy was embroiled in an effort to remove her name from the notorious McCarthy-era Hollywood blacklist of possible communist sympathizers.