13 in
Find the perimeter by adding the lengths of the sides
-- Measure or calculate the length of each of its 3 sides. -- Add the lengths of its 3 sides. -- The sum is the perimeter of the triangle.
The perimeter of a triangle is equal to the length of its three sides added together. If you do not know the lengths of the sides, there are many different mathematical techniques for discovering them.
Add the lengths of the 3 sides to get the perimeter.
-- Make sure you have the lengths of all three sides -- Add up the lengths of all three sides to get the perimeter of the triangle.
you add up the measures of the sides Perimeter=a+b+cAdd up the three sides together
It is the sum of the lengths of the three sides. However, since all three sides are of the same length, the perimeter equals three times the length of any one side.
you multiply one of the sides by three. The perimeter is the total length of the outside of the shape - in this case the total of the lengths of the three sides. You'll need to know the length of one side and an angle to calculate the lengths of the others in any triangle, however in an equilateral triangle all the sides are the same length so if you know one you know them all.
The perimeter formula of a triangle is the sum of the lengths of all three sides. Mathematically, it can be expressed as P = a + b + c, where P is the perimeter and a, b, and c are the lengths of the three sides of the triangle.
A perimeter of a triangle is the sum of all three lengths on the sides.
It is the sum of the lengths of its sides.
is the sum of the lengths of the three sides.