Mark four points $\mathrm{P}, \mathrm{Q}, \mathrm{R}, \mathrm{S}$ such that no three of them lie on the same line. Draw lines through the points taken two at a time. How many lines can you draw?

Categorise the curve given below as open, closed, complex and simple curves.

Categorise the curve given below as open, closed, complex and simple curves.

Categorize the curve given below as open, closed, complex, and simple curves.