Identify the odd term: 16, 25, 36, 72, 144, 196, 225.

Introduction / Context:
This list contains mostly perfect squares; the aim is to pick the solitary non-square. Recognizing squares up to at least 15^2 is enough to answer confidently.

Given Data / Assumptions:

• 16 = 4^2, 25 = 5^2, 36 = 6^2
• 144 = 12^2, 196 = 14^2, 225 = 15^2
• 72 is not a perfect square

Concept / Approach:
Check each number for being an exact square. One term will not match any n^2 with integer n; that is the odd one out.

Step-by-Step Solution:
Confirm squares: 16, 25, 36, 144, 196, 22572 falls between 8^2 = 64 and 9^2 = 81 → not a squareHence 72 is the odd term

Verification / Alternative check:
Prime factorization: 72 = 2^3 * 3^2 — an odd exponent remains, so it cannot be a perfect square.

Why Other Options Are Wrong:
36/196/225 are perfect squares and conform to the theme.

Common Pitfalls:
Confusing 144 as non-square; it is 12^2. Rapid recognition of common squares prevents such slips.

Final Answer:
72