So, we have x + 2x = 90. Solving for x, we get x = 30. Since the first angle was called x, that means it's measurement is 30°. The second angle, 2x, is just twice the first angle, so its measurement is 60°
A point is a location. On the 2D coordinate plane, it's described by (x,y). Think of it like an address or like latitude/longitude. A point is an undefined term in geometry as it doesn't build off of smaller elements.