Assertion : Side of the square whose area is 225 sq. m is 15 m.
Reason : The standard unit of area is sq. units.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true and reason is not the correct explanation of assertion.
C. If assertion is true but reason is false.
D. If assertion is false but reason is true.

Answer

To solve the question, we need to analyze both the assertion and the reason provided.

### Step 1: Understand the Assertion
The assertion states that the side of a square whose area is 225 square meters is 15 meters.

### Step 2: Recall the Formula for the Area of a Square
The area \( A \) of a square is given by the formula:
\[ A = \text{side}^2 \]
where "side" is the length of one side of the square.

### Step 3: Set Up the Equation
According to the assertion, the area \( A \) is 225 square meters. Therefore, we can set up the equation:
\[ \text{side}^2 = 225 \]

### Step 4: Solve for the Side Length
To find the length of the side, we take the square root of both sides:
\[ \text{side} = \sqrt{225} \]

### Step 5: Calculate the Square Root
Calculating the square root:
\[ \text{side} = 15 \text{ meters} \]

### Step 6: Conclusion on the Assertion
The assertion is correct because the side of the square is indeed 15 meters.

### Step 7: Understand the Reason
The reason states that the standard unit of area is square units. This is also true, as area is measured in square units (e.g., square meters).

### Step 8: Analyze the Relationship
While both the assertion and reason are true, the reason does not explain why the side of the square is 15 meters. The reason simply states a fact about the units of measurement.

### Final Conclusion
Both the assertion and reason are correct, but the reason is not the correct explanation of the assertion. Therefore, the correct answer is that both are true, but the reason does not explain the assertion.

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