Discrete Mathematics
# Rule of Sum and Rule of Product

How many triangles are there in the diagram above?

How many 4 -digit positive integers have 2 or more zeroes?

How many parallelograms are formed when a set of 5 parallel lines intersects a set of 4 parallel lines?

**Details and Assumptions**

- All parallel lines are extended indefinitely.

How many triangles are there in the above image?