How big is a 12 by 12 room?

To solve for area:

A=lw (Area equals length times width)

The length and width are both 12. Substitute 12 for l and w.

A=12x12

Multiply.

A=144

The room has an area of 144 units.

To solve for perimeter:

P=2l+2w (Perimeter equals two time the length plus two times the width).

Substitute 12 for l and w.

P=(2x12)+(2x12)

Simplify.

P=24+24

P=48

The room has a perimeter of 48 units.