What are you trying to do? You might not need to use something complicated. Here's the most common types of 2D collision detection.
Axis-Aligned Bounding Box (AABB)
Checks if there is a gap between two rectangles. Axis-aligned means that there is no rotation. This is what GSAP uses for Draggable's hit test.
Checks for a collision between two circles by comparing the sum of their radii with the distance between the center of the two circles. Really simple to do...