Find the perimeter of each of the following shapes :
A triangle of sides 3 cm, 4 cm and 5 cm.

Answer

To find the perimeter of a triangle with sides measuring 3 cm, 4 cm, and 5 cm, follow these steps:

### Step-by-Step Solution:

1. **Identify the sides of the triangle**:
The sides of the triangle are given as:
- Side 1 = 3 cm
- Side 2 = 4 cm
- Side 3 = 5 cm

2. **Formula for the perimeter of a triangle**:
The perimeter (P) of a triangle is calculated by adding the lengths of all its sides. The formula is:
\[ P = \text{Side 1} + \text{Side 2} + \text{Side 3} \]

3. **Substitute the values into the formula**:
Now, substitute the values of the sides into the formula:
\[ P = 3 \, \text{cm} + 4 \, \text{cm} + 5 \, \text{cm} \]

4. **Perform the addition**:
- First, add the first two sides:
\[ 3 \, \text{cm} + 4 \, \text{cm} = 7 \, \text{cm} \]
- Then, add the result to the third side:
\[ 7 \, \text{cm} + 5 \, \text{cm} = 12 \, \text{cm} \]

5. **State the final result**:
Therefore, the perimeter of the triangle is:
\[ P = 12 \, \text{cm} \]