Question

c) Area of triangle formed by points A (1, 2), B (-1, 3) and C (4, k) is 8 square units then value of k is ?​

Answer 1

Answer:

Explanation:

Area of triangle

= √x1(y2 - y3) + x2(y3 - y1) + x3(y1 - y2)

Here,

x1 = 1

x2 = -1

x3 = 4

y1 = 2

y2 = 3

y3 = k

To find :-

Value of k

Substituting values in formula,

√1(3 - k) + (-1)(k - (-2) + 4(2 - 3) = 8

√1(3 - k) - 1(k + 2) +4(-1) = 8

√3 - k - k - 2 - 4 = 8

√3 - 2 - 4 - 2k = 8

√- 3 - 2k = 8

- 3 - 2k = 64

- 2k = 64 + 3

- 2k = 67

k = -67/2

•°• Value of k is -67/2