A rectangle is NOT <em>always </em>a square because a square has congruent sides, so that means all four of its sides are <em>always </em>equal.
A rectangle <em>can </em>be a square but it can also not be a square, so therefore A cannot be an option because it is not always true about a rectangle.
B. the sum of its angle measures is 360
This is true because every quadrilateral's angle measures will add up to 360 degrees, no matter what. This is like how a triangle's angle measures always add up to 180 degrees.
B is an option because it is an ALWAYS true statement.
C. it has four congruent angles
A rectangle always has 90 degree angles, giving it its shape.
Since a rectangle always has the same-degree angles, that means that it DOES have four congruent angles.
C is also an option because it is always true.
D. it has four congruent sides
A rectangle does not ALWAYS have four congruent sides. Say for example a rectangle has a longer length than its width.
A square has four congruent sides, but a rectangle is not always a square, therefore this option is not applicable for a rectangle since it is not always true.
