What is the area of the triangle with vertices (1, -1), (-4, 6) and (-3, -5)?
Answer: B
The area of a triangle with vertices \((x_1, y_1), (x_2, y_2), (x_3, y_3)\) is given by the formula:
Area = \(\frac{1}{2} |x_1(y_2-y_3) + x_2(y_3-y_1) + x_3(y_1-y_2)|\)
Area = \(\frac{1}{2} |1(6 - (-5)) + (-4)(-5 - (-1)) + (-3)(-1 - 6)|\)
Area = \(\frac{1}{2} |1(11) + (-4)(-4) + (-3)(-7)|\)
Area = \(\frac{1}{2} |11 + 16 + 21| = \frac{1}{2} |48| = 24\) sq units.