a. Converse: If the interior angles of a shape do not sum to 180°, then the shape is not a triangle. The converse is true. If the interior angles do not add up to 180°, it implies that the shape is not a triangle.
b. Converse: If alternate interior angles of two lines are equal, then the lines are parallel. The converse is true. If alternate interior angles are equal, it implies that the lines are parallel.
c. Converse: If I have a Rhombus, then I also have a Square. The converse is not true. A rhombus is a parallelogram with equal side lengths, but it does not necessarily have right angles like a square.
d. Converse: If I have a shape with four right angles, then I have a rectangle. The converse is not true. A shape with four right angles could be a square, but it could also be a parallelogram or a rhombus.