Question

Find the area of a triangle with vertices A(3, 1), B(2, -1), and C(-2, 1). Leave your answer in decimal form, rounded to the nearest hundredth.

Answer 1

5

Explanation:

the area can be calculated using the formula (it is based on the vectors):

`A=(1)/(2) *|\left[\begin{array}{ccc}{X_A-X_C}&Y_A-Y_C\\X_B-X_C&Y_B-Y_C\\\end{array}\right]|;`

if to substitute the coordinates of the given points, then:

`A=(1)/(2)*|\left[\begin{array}{ccc}5&0\\4&-2\\\end{array}\right]|=(1)/(2)*10=5.`

note: the suggested option is not the only one.