How does the angle of the sun in the sky effect the seasons?

The angle of the sun in the sky effects the seasons because of the tilt on the axis the earth is on while rotating around the sun. The more sunlight the earth gets the warmer the weather, the less light the colder hence we get summer and winter 

The amount of heat energy received at any location on the globe is a direct effect of Sun angle on climate, as the angle at which sunlight strikes the Earth varies by location, time of day, and season due to the Earth's orbit around the Sun and the Earth's rotation around its tilted axis. ... (See also season.)