1. **State the problem:** Find the value of $a^2$ when $a = 6$. 2. **Formula used:** The expression $a^2$ means $a$ multiplied by itself, so $$a^2 = a \times a$$ 3. **Substitute the value:** Replace $a$ with 6: $$6^2 = 6 \times 6$$ 4. **Calculate:** $$6 \times 6 = 36$$ 5. **Final answer:** $$a^2 = 36$$ So, when $a = 6$, the value of $a^2$ is 36.