Find the area of the rectangle.

L = 13m and H = 3m

Do I multiply or do I add?

Always multiply when you're finding the area.

http://www.mathplayground.com/area_perimeter.html

Great! So the answer is 39! :D

39 SQUARE meters

To find the area of a rectangle, you need to multiply the length (L) by the height (H).

In this case, the length (L) is 13m and the height (H) is 3m.

So, to find the area, you need to multiply 13m by 3m.
The formula for the area of a rectangle is:

Area = Length * Height

Therefore, the area of this rectangle is 13m * 3m = 39 square meters.