Question

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

Answer 1

Answer:

k = -3

Step-by-step explanation:

Area of the triangle = 15

$\frac{1}{2}[$x₁(y₂-y₃) + x₂(y₃-y₁)+x₃(y₁-y₂)] = 15

$\frac{1}{2}[1(k-7)+4(7+3)-9(-3-k) = 15$

k - 7 + (4 × 10 ) +27 +9k = 15

60 + 10k = 30

10k = -30

k= $\frac{-30}{10}$ = -3