Perimeter of a Triangle Worksheets - Free Printable

To find the perimeter of a triangle, you simply add up the lengths of all three sides.

Here are the step-by-step calculations for each problem:

1)
Sides: $3\frac{1}{2}$, $4$, $5$
Perimeter = $3.5 + 4 + 5 = 12.5$ (or $12\frac{1}{2}$)

2)
Sides: $\frac{1}{2}$, $\frac{3}{4}$, $\frac{1}{4}$
First, add $\frac{3}{4} + \frac{1}{4} = \frac{4}{4} = 1$.
Then add the remaining side: $1 + \frac{1}{2} = 1\frac{1}{2}$ (or $1.5$)

3)
Sides: $\frac{1}{2}$, $\frac{1}{2}$, $\frac{1}{2}$
Perimeter = $\frac{1}{2} + \frac{1}{2} + \frac{1}{2} = \frac{3}{2} = 1\frac{1}{2}$ (or $1.5$)

4)
Sides: $2\frac{1}{4}$, $3$, $4\frac{1}{2}$
Add whole numbers: $2 + 3 + 4 = 9$
Add fractions: $\frac{1}{4} + \frac{1}{2} = \frac{1}{4} + \frac{2}{4} = \frac{3}{4}$
Total Perimeter = $9\frac{3}{4}$ (or $9.75$)

5)
Sides: $\frac{3}{8}$, $\frac{5}{8}$, $\frac{7}{8}$
Perimeter = $\frac{3+5+7}{8} = \frac{15}{8}$
Convert to mixed number: $15 \div 8 = 1$ with a remainder of $7$.
Total Perimeter = $1\frac{7}{8}$ (or $1.875$)

6)
Sides: $\frac{1}{3}$, $\frac{2}{3}$, $\frac{1}{3}$
Perimeter = $\frac{1+2+1}{3} = \frac{4}{3}$
Convert to mixed number: $4 \div 3 = 1$ with a remainder of $1$.
Total Perimeter = $1\frac{1}{3}$ (approx $1.33$)

7)
Sides: $\frac{1}{2}$, $\frac{3}{4}$, $\frac{5}{8}$
Find a common denominator (which is 8):
$\frac{1}{2} = \frac{4}{8}$
$\frac{3}{4} = \frac{6}{8}$
$\frac{5}{8} = \frac{5}{8}$
Add them up: $\frac{4+6+5}{8} = \frac{15}{8}$
Total Perimeter = $1\frac{7}{8}$ (or $1.875$)

8)
Sides: $1\frac{1}{4}$, $2$, $3\frac{1}{2}$
Add whole numbers: $1 + 2 + 3 = 6$
Add fractions: $\frac{1}{4} + \frac{1}{2} = \frac{1}{4} + \frac{2}{4} = \frac{3}{4}$
Total Perimeter = $6\frac{3}{4}$ (or $6.75$)

9)
Sides: $\frac{1}{2}$, $\frac{1}{3}$, $\frac{1}{6}$
Find a common denominator (which is 6):
$\frac{1}{2} = \frac{3}{6}$
$\frac{1}{3} = \frac{2}{6}$
$\frac{1}{6} = \frac{1}{6}$
Add them up: $\frac{3+2+1}{6} = \frac{6}{6} = 1$
Total Perimeter = $1$

Final Answer:
1) $12\frac{1}{2}$
2) $1\frac{1}{2}$
3) $1\frac{1}{2}$
4) $9\frac{3}{4}$
5) $1\frac{7}{8}$
6) $1\frac{1}{3}$
7) $1\frac{7}{8}$
8) $6\frac{3}{4}$
9) $1$