1. **State the problem:** Evaluate the expression $3 + a^2$ when $a = 5$. 2. **Recall the order of operations (PEMDAS):** Parentheses, Exponents, Multiplication and Division (left to right), Addition and Subtraction (left to right). 3. **Apply the value of $a$:** Substitute $a = 5$ into the expression: $$3 + 5^2$$ 4. **Calculate the exponent first:** $$5^2 = 25$$ 5. **Substitute back:** $$3 + 25$$ 6. **Perform the addition:** $$3 + 25 = 28$$ **Final answer:** $28$