If the two vertices of a triangle are (5, 4), and (-2, 4) and the centroid is (5, 6), then the third vertex is: |
(10, 12) (-10, 12) (12, -10) (12, 10) |
(12, 10) |
The correct answer is Option (4) → (12, 10) Let the third vertex be (x, y). The centroid $(G_x, G_y)$ of a triangle with vertices $(x_1, y_1), (x_2, y_2), (x_3, y_3)$ is given by: $\left(\frac{x_1+x_2+x_3}{3}, \frac{y_1+y_2+y_3}{3}\right)$ Given:
So, $\frac{5 + (-2) + x}{3} = 5$ $\frac{4 + 4 + y}{3} = 6$ Solve for x: $\frac{3 + x}{3} = 5 \Rightarrow 3 + x = 15 \Rightarrow x = 12$ Solve for y: $\frac{8 + y}{3} = 6 \Rightarrow 8 + y = 18 \Rightarrow y = 10$ So, the third vertex is: $(12, 10)$ |