The figure (3,12,9,3) contains only horizontal and vertical lines. Calculate its perimeter.

30 square units

Step-by-step explananation:

First of all we need to know the formula to finding the perimeter of a rectangle which is:

P = 2 x L (Length) + 2 x h (Height)

12 and 3 are apart by 12 - 3

12 - 3 = 9

Then, we subtract 9 from 3 (:

9 - 3 = 6)

To get 6 as our answer.

6 will be the width and 9 will be the length.

Now we solve for the perimeter by plugging in our values into our formula:

P = 2 (9) + 2 (6)

P = 18 + 12

P = 30 square units