Find the square of :
`sqrt(5)-2`

Answer

To find the square of \( \sqrt{5} - 2 \), we can use the identity for the square of a binomial, which is:

\[ (A - B)^2 = A^2 - 2AB + B^2 \]

### Step-by-step solution:

1. **Identify A and B**: In our case, we have:
- \( A = \sqrt{5} \)
- \( B = 2 \)

2. **Apply the identity**: Substitute \( A \) and \( B \) into the identity:
\[ (\sqrt{5} - 2)^2 = (\sqrt{5})^2 - 2 \cdot \sqrt{5} \cdot 2 + (2)^2 \]

3. **Calculate \( A^2 \)**:
\[ (\sqrt{5})^2 = 5 \]

4. **Calculate \( B^2 \)**:
\[ (2)^2 = 4 \]

5. **Calculate \( -2AB \)**:
\[ -2 \cdot \sqrt{5} \cdot 2 = -4\sqrt{5} \]

6. **Combine the results**: Now, substitute back into the equation:
\[ (\sqrt{5} - 2)^2 = 5 - 4\sqrt{5} + 4 \]

7. **Simplify**: Combine the constant terms:
\[ 5 + 4 = 9 \]
So, we have:
\[ (\sqrt{5} - 2)^2 = 9 - 4\sqrt{5} \]

### Final Answer:
\[ (\sqrt{5} - 2)^2 = 9 - 4\sqrt{5} \]