Q.Why is it called an isoceles triangle?
A.Because only two of its sides are equal.

Q.How many sides has it?
A.Three, the same as the other.

Q.Are there any other kind of isoceles triangles?
A.Yes, there are right-angled and obtuse-angled.
[Here the other triangles are to be shewn, and the master must explain to the children the meaning of right-angled and obtuse-angled.] _Scalene Triangle_.
Q.What is this?
A.An acute-angled scalene triangle.

Q.Why is it called an acute-angled scalene triangle?
A.Because all its angles are acute, and its sides are not equal.

Q.Why is it called scalene?
A.
Because it has all its sides _unequal_.