What is the area of the triangle in square units?

Point A: (0, 3)
Point B: (10, 6)
Point C: (6, 3)

A. 18
B. 9
C. 15
D. 6

1 answer

To find the area of a triangle given its vertices, we can use the formula:

\[ \text{Area} = \frac{1}{2} \left| x_1(y_2 - y_3) + x_2(y_3 - y_1) + x_3(y_1 - y_2) \right| \]

where \( (x_1, y_1) \), \( (x_2, y_2) \), and \( (x_3, y_3) \) are the coordinates of the vertices A, B, and C, respectively.

Given the points:

  • \( A(0, 3) \) \( (x_1 = 0, y_1 = 3) \)
  • \( B(10, 6) \) \( (x_2 = 10, y_2 = 6) \)
  • \( C(6, 3) \) \( (x_3 = 6, y_3 = 3) \)

Plugging in these coordinates into the area formula:

\[ \text{Area} = \frac{1}{2} \left| 0(6 - 3) + 10(3 - 3) + 6(3 - 6) \right| \]

Calculating each term:

  1. \( 0(6 - 3) = 0 \)
  2. \( 10(3 - 3) = 10 \cdot 0 = 0 \)
  3. \( 6(3 - 6) = 6 \cdot -3 = -18 \)

Now substituting these values back into the area formula:

\[ \text{Area} = \frac{1}{2} \left| 0 + 0 - 18 \right| = \frac{1}{2} \left| -18 \right| = \frac{1}{2} \cdot 18 = 9 \]

Thus, the area of the triangle is \( \text{9} \) square units.

The answer is: B. 9.