Find the area of the following polygon.

Regular hexagon of side $5 cm$

Find the area of the following polygon in hectares:

Find the area of the polygon:

Find the area of the polygon:

Find the area of the following field:

The total surface area of a cone of radius $3$ cm and height $4$ cm is _____ ${\text{cm}}^2\text{.}$

Euler's formula is given by 

How many equal triangular faces does a regular pentagonal pyramid have?