Question

the vertices of a triangle are (1, k),(4, -3), (- 9,7) and its area is 15 sq. units, find the values of k.​

Answer 1

Answer:

Use the herons formula

Step-by-step explanation:

Answer 2

Step-by-step explanation:

Area of triangle = 15 unit²

1/2 * {x1(y2 - y3) + x2(y3 - y1) + x3(y1 - y2)} = 15

{ 1 (-3 - 7) + 4 (7 - k) + (-9) ( k + 3) } = 30

{ 1 (-10) + 28 - 4k - 9k - 27 } = 30

{ -10 + 28 - 13k - 27 } = 30

- 13k -9 = 30

- 13k = 39

13k = -39

k = -3