How many dimensions does a point have?

Read the following statement:
An equilateral triangle is a polygon made up of three line segments out of which two line segments are equal to the third one and all its angles are $60^{\circ}$ each.
Define the terms used in this definition which you feel necessary. Are there any undefined terms in this? Can you justify that all sides and all angles are equal in an equilateral triangle?

If $P$,$Q$,and $R$ are three points on a line,and $Q$ lies between $P$ and $R$ [see figure],then prove that $PQ + QR = PR$.

The boundaries of the solid are ...........

How many dimensions does a line have?

The number of interwoven $\ldots \ldots$ triangles in Sriyantra (in the Atharvaveda) is nine.