An equilateral triangle has three sides of equal measure, so divide its perimeter by :

To find the perimeter of a triangle, we will use the following formula:

where a, b, and c are the lengths of the sides of the triangle.

Now, we know the base of the equilateral triangle is 11in.  Because it is an equilateral triangle, all sides are equal.  Therefore, all sides are 11in.  

So, we can substitute.  We get

An isosceles triangle has two sides of equal length. If two sides of an isoscelese triangle are of length 12 and 13, then the third must be of length 12 or 13.

This makes the perimeter either

or

Of our choices, we choose 38.

So this question requires you to know the formula for area for a square which is side squared.  

Thus, , so one side is the square root of 16, or 4.  

To figure out the perimeter, add up all of the sides of the square which are all the same (4).

A square has four sides of equal measure, so divide its perimeter by 4:

One foot is equal to 12 inches, so the perimeter 16 feet 4 inches is equal to  inches.

An square has four sides of equal measure, so divide its perimeter by 4:

To convert 49 inches to feet and inches:

One side measures 4 feet 1 inch.

The perimeter of a shape is the distance around the outside boundry of that shape.

In order to find the perimeter, add up the lengths of the sides of that shape.

Because a square has four equal sides, add  to find the perimeter. Equivalently, multiply .

Finding perimeter is easiest with squares. Perimeter is the distance around the outside of the figure. There are two good ways to find the perimeter. The first and longer method of finding perimeter is simply to add up the length of each side. Thus, we would take the length of top of the square and add it to the length of the right side. We'd continue all the way around. The formula for this method could be written like so: 

top + right side + bottom + left side = perimeter.

Since a square has equal sides all around, we could also write the formulalike so:

The second and easier way of finding perimeter for a square is a simplification of the first method. Instead of adding the same number four times we could simply multiply by 4. Written as a formula, this would look like this:

For the this question, your work should then look like one of these two options:

or

Finding perimeter is easiest with squares. Perimeter is the distance around the outside of the figure. There are two good ways to find the perimeter. The first and longer method of finding perimeter is simply to add up the length of each side. Thus, we would take the length of top of the square and add it to the length of the right side. We'd continue all the way around. The formula for this method could be written like so: 

top + right side + bottom + left side = perimeter.

Since a square has equal sides all around, we could also write the formulalike so:

The second and easier way of finding perimeter for a square is a simplification of the first method. Instead of adding the same number four times we could simply multiply by 4. Written as a formula, this would look like this:

For the this question, your work should then look like one of these two options:

or

Finding perimeter is easiest with squares. Perimeter is the distance around the outside of the figure. There are two good ways to find the perimeter. The first and longer method of finding perimeter is simply to add up the length of each side. Thus, we would take the length of top of the square and add it to the length of the right side. We'd continue all the way around. The formula for this method could be written like so: 

top + right side + bottom + left side = perimeter.

Since a square has equal sides all around, we could also write the formulalike so:

The second and easier way of finding perimeter for a square is a simplification of the first method. Instead of adding the same number four times we could simply multiply by 4. Written as a formula, this would look like this:

For the this question, your work should then look like one of these two options:

or