Math perimeter and area in the coordinate plane

1 answer

Perimeter and area calculations can be done for geometric shapes in the coordinate plane using formulas derived from the coordinates of the points of the shape.

For a rectangle with opposite corners at points (x1, y1) and (x2, y2), the perimeter can be calculated using the formula:

Perimeter = 2 * (|x2 - x1| + |y2 - y1|)

The area of the rectangle can be calculated using the formula:

Area = |x2 - x1| * |y2 - y1|

Similarly, for a triangle with vertices at points (x1, y1), (x2, y2), and (x3, y3), the perimeter can be calculated by summing the lengths of the sides of the triangle:

Perimeter = |x2 - x1| + |x3 - x2| + |x1 - x3| + |y2 - y1| + |y3 - y2| + |y1 - y3|

The area of a triangle can be calculated using the formula for the determinant of a matrix (called the shoelace formula):

Area = 0.5 * |x1(y2 - y3) + x2(y3 - y1) + x3(y1 - y2)|

By using these formulas, the perimeter and area of geometric shapes in the coordinate plane can be calculated based on the coordinates of their vertices.