Draw rough sketches of concave and convex quadrilaterals. Explain the properties which differentiate them.

The length of the longest chord of a circle of radius $5 \mathrm{cm}$ is

State True or False:

If $a,b,c$ are any three whole numbers, then $\left(a\times b\right)\times c=a\times \left(b\times c\right)$.

Whole number _____ can never be a divisor.

The interior of a circle along with the circle is known as _____ region .