Question

In 1/2|x1(y2-y3)+x2(y3-y1)+x3(y1-y2)|. What is the meaning of "|" in this

Answer 1

| a| means modulus of a. Whether the value of a is either positive or negative modulus means always positive and negative should be removed.

Here, formula for area of ∆ is given. Final answer should be positive value only (modulus of positive or negative is always positive) and value of area should be positive only.