public void Area_IsSameAsForTriangleWithGivenSides()
{
var triangle = new Triangle(3, 4, 5);
var expected = triangle.Area();
var polygon = new SimplePolygonBuilder()
.Add(new Point(0, 0))
.Add(new Point(4, 0))
.Add(new Point(0, 3))
.Close();
var actual = polygon.Area();
Assert.Equal(expected, actual);
}
public void Area_IsSameForRectangleWithGivenSides()
{
var expected = 4 * 3; // Rectangle with sides 4 and 3
var polygon = new SimplePolygonBuilder()
.Add(new Point(0, 0))
.Add(new Point(4, 0))
.Add(new Point(4, 3))
.Add(new Point(0, 3))
.Close();
var actual = polygon.Area();
Assert.Equal(expected, actual);
}
public void Area_CorrectForNonTrivialShape()
{
// Consider rectangle with sliced out right triangle inside.
// Rectangle with sides 7 and 6, triangle with catheti
// 3 and 4. Meaning, area is equal 7 * 6 - 3 * 4 / 2
var expected = 7 * 6 - new Triangle(3, 4, 5).Area();
var polygon = new SimplePolygonBuilder()
.Add(x: 0, y: 0)
.Add(x: 3, y: 0)
.Add(x: 7, y: 3)
.Add(x: 7, y: 6)
.Add(x: 0, y: 6)
.Close();
var actual = polygon.Area();
Assert.Equal(expected, actual);
}