Many species of fungus exist in the environment, but only some cause infections. The primary source of most infections is soil. Fungal infections can be acquired by inhalation, ingestion, or through the skin (for example, through a cut or wound).
Squares are quadrilaterals in which all four sides and all four angles have equal measurements. Rectangles have four angles with equal measurements, and the opposite sides also have equal measurements. All squares are rectangles, but not all rectangles are squares. Trapezoids have exactly one pair of parallel sides. Rhombuses have four sides with equal measurements, and opposite pairs of sides are parallel. All rhombuses are parallelograms, but not all parallelograms are rhombuses. All squares are rhombuses, but not all rhombuses are squares.
2. If both pairs of opposite sides of a quadrilateral are congruent, then it is a parallelogram. 3. If one pair of opposite sides of a quadrilateral are both parallel and congruent, then it is a parallelogram. 4. If the diagonals of a quadrilateral bisect each other, then the it is a parallelogram. 5.. If both pairs of opposite angles of a quadrilateral are congruent, then it is a parallelogram. Proving That a Quadrilateral is a Rectangle One can prove that a quadrilateral is a rectangle by first showing that it is a parallelogram and then using either of the following methods to complete the proof.