If you mean vertices of: (-1, -1) (-1, 3) and (5, -1) then when plotted on the Cartesian plane it will form a right angle triangle with a base of 6 units and a height of 4 units.
Area of triangle: 0.5*6*4 = 12 square units
Select any one of the vertices and draw all the diagonals from that vertex. This will divide the polygon (with n sides) into n-2 triangles. Use the coordinates of the vertices of each triangle to calculate its area, and then add the areas of these triangles together.
The area of triangle is : 80.0
The area is calculated easily using the determinant of the matrix of coordinates, or Heron's formula and is 15 square units.
The base of the right-angled triangle = 4 units The height = 6 units The area = 0.5 * base * height = 12 square units =========================
Assuming that these are coordinates of the vertices, the area is 6 square units.
The area of triangle is : 100.0
It is an isosceles triangle with a perimeter of 26+(4 times square root of 13) linear units and an area of 78 square units
The area of triangle is : 90.0
By plotting the given vertices and then joining them together on the Cartesian plane the shape of a isosceles triangle will be formed with an area of 78 square units.
The area of triangle is : 100.0
The area of triangle is : 60.0
84.87