Area of the square paper = 15 &times; 15 = 225 cm&sup2;.<br><br>Area of the triangle cut out = \( \frac{1}{2} \times \text{base} \times \text{height} \) = \( \frac{1}{2} \times 4 \times 5 = 10 \) cm&sup2;.<br><br>Area of remaining paper = 225 &minus; 10 = 215 cm&sup2;.<br><br>Final Answer: B: 215 cm&sup2;