Constructive and Destructive Wave Interferences

So we've learned about waves recently. And it's more...geometric then I thought.
There are apparently two types of wave interferences, and you can probably guess what they are from the title.
Firstly, the basic parts of the wave is as shown:

When two waves from each side collides with each other, they combine with each other. Two waves colliding in the same direction vertically is called a constructive interference. It's when the waves involved is a crest and a crest, or a trough and a trough. When they meet, the shapes of the waves combine on top of each other, and then they go back on their seperate ways.

When the two waves of different directions vertically collide, it is called a destructive interference. This would be when a trough and a crest are involved. These two combine as well, but one negates another.