Perimeter Math Example 2

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Example 2

medium
A triangle has sides measuring 77 cm, 1010 cm, and 1212 cm. Find its perimeter.

Solution

  1. 1
    The perimeter of a polygon is the total length of its boundary: add every side once.
  2. 2
    Identify the three sides: a=7a = 7 cm, b=10b = 10 cm, c=12c = 12 cm. Apply P=a+b+cP = a + b + c.
  3. 3
    Compute: P=7+10+12=29P = 7 + 10 + 12 = 29 cm. Since the largest side (12) is less than the sum of the other two (7+10=177 + 10 = 17), the triangle inequality is satisfied, confirming this is a valid triangle.

Answer

P=29 cmP = 29 \text{ cm}
For any polygon, the perimeter is simply the sum of all side lengths. Unlike rectangles, a general triangle may have three different side lengths, so we add each one individually.

About Perimeter

The total distance around the outside of a two-dimensional shape, found by adding all its side lengths.

Learn more about Perimeter →

More Perimeter Examples

Example 1 easy

Find the perimeter of a rectangle with length [formula] cm and width [formula] cm.

Example 3 easy

Find the perimeter of a square with side length [formula] m.

Example 4 medium

The length of a rectangle is [formula] m more than twice its width. If its perimeter is [formula] m,

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