No. You don't. Don't do it.
Just add them - 24 inches.
78.7 inches.
Yards and feet. You may add the inches if needed, to be absolutely precise. 'Mary's boat is 4 yards, 2 feet and 3 inches long.'
You, add S1+S2+S3+S4=7+7+2+2= 18with the unit of measure so like inches it would be18infeet18ft18m18km
2 inches = 5.08 cm
You add the lengths of all the sides together. For an example, if the sides of a triangle were: 2 inches, 3 inches, and 5 inches, you would add 2, 3, and 5 together to get 10 inches.
Look on a tape measure, 13' 2"
That would be 28 inches.
31 inches or 78.74cm or 0.7874m
-- Measure the length of the base, in inches. -- Measure the height of the triangle, in inches. -- Multiply the two numbers and take 1/2 of the product. 1/2 of the product is the area of the triangle, in square inches.
Using Pythagoras' theorem it is 2 inches
multiply feet by 12 and add inches; then minus inches. Example: 2 feet 2 inches minus 5 inches = 26-5 = 21 inches