How to change into Inches?

Multiply by 12

12' = 144"
3' = 36"

The last one is already in inches

12 feet = 12 * 12
12 feet = 144 inches

3 feet = 3 * 12
3 feet = 36 inches

4 inches is already the conversion unit of measure

1 foot = 12 inches
12 feet = 144 inches
3 feet = 36 inches
4 inches = 4 inches

12 ft = 12"(12') = 144"
3 ft = 12"(3') = 36"
4 in. = 4"
You just multiply the # of inches in a foot (12) by the # of feet you have.

12 inches per foot so

12x12=144 inches
3x12=36 inches
4 inches=4 inches

1 ft = 12 inch.

12 ft = 12 x 12 = 144 inches

3 Ft = 3 x 12 = 36 inches....

1 foot = 12 inches
12 feet = 12 x 12 inches = 144 inches
3 feet = 3 x 12 inches = 36 inches

1 Ft = 12 inches, so multiply the first two by 12

the are several conversion calculators that do the work for you. just type "conversion Chart" into to search and you'll find one