Interpretação geométrica do determinante 2x2 e de suas propriedades com aplicações na geometria analítica

Abstract

This paper presents a way to calculate the area of triangles are known when the coordinates of three of its vertices that is different from what you see in high school texts. Given three points of a triangle, this is associated with a parallelogram in the coordinate plane and an 2x2 matrix whose determinant, in absolute value, measure the area of the parallelogram that is twice the area of the triangle. Thus, the properties of algebraic determinants 2nd order that are taught in high school can also be interpreted geometrically enriching the geometric meaning of these properties. This paper also presents a sequence of topics organized in a didactic manner which can be used by teachers in teaching and determinant of analytic geometry in high school.