If `L=2.331cm`,`B=2.1cm`, then `L+B=

Options

A. 4.431cm
B. 4.43 cm
C. 4.4 cm
D. 4 cm

Explanation

To solve the problem of adding the lengths \( L \) and \( B \) while considering significant figures, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Values**:
- Given \( L = 2.331 \, \text{cm} \)
- Given \( B = 2.1 \, \text{cm} \)

2. **Add the Values**:
- Perform the addition:
\[ L + B = 2.331 \, \text{cm} + 2.1 \, \text{cm} \]
- To add these, align the decimal points:
\[ \begin{array}{r} 2.331 \\ + 2.100 \\ \hline 4.431 \, \text{cm} \end{array} \]

3. **Determine Significant Figures**:
- Identify the number of significant figures in each value:
- \( L = 2.331 \) has 4 significant figures.
- \( B = 2.1 \) has 2 significant figures.
- The result should be reported with the same number of decimal places as the measurement with the least number of decimal places, which is \( B \) (2 significant figures).

4. **Round the Result**:
- The result from the addition is \( 4.431 \, \text{cm} \).
- To round \( 4.431 \) to 2 significant figures:
- The first two significant figures are \( 4.4 \).
- The next digit (3) is less than 5, so we do not round up.
- Thus, the rounded result is \( 4.4 \, \text{cm} \).

5. **Final Answer**:
- Therefore, the final answer is:
\[ L + B = 4.4 \, \text{cm} \]