Answer: 3×3 determinant.
- A 3×3 determinant
- B 2×2 determinant
- C 1×1 determinant
- D 4×4 determinant
Correct answer: A. 3×3 determinant
Explanation: The area formula uses a 3×3 determinant built from the coordinates of the three vertices.
Concept context
Evaluation of determinants, cofactors, adjoint, inverse of matrix, Cramer's rule and area applications. Always in board and JEE.