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.
A triangle can be thought of as half of a rectangle when there is a right angle. The area of the triangle will be . Two special quadrilaterals that we will examine are the parallelogram and the trapezoid. A parallelogram is a quadrilateral with both pairs of opposite sides parallel. A trapezoid is a quadrilateral with only one pair of opposite sides parallel. The perimeters of each are the sum of the lengths of the sides.