The avian cardiovascular system is able to quickly respond to changes in levels of activity (e.g., resting vs. flying) via changes in heart rate, cardiac output, & blood flow (by vasocontriction and vasodilation of vessels).
A square is a quadrilateral with all right angles and all equal sides. A square is also a parallelogram, a rectangle, and a rhombus and has all the properties of all these special quadrilaterals. Figure 3 shows a square. Figure 3 A square has four right angles and four equal sides. Figure 4 summarizes the relationships of these quadrilaterals to one another.
A rectangle can be thought about in other ways: A square is a special case of a rectangle where all four sides are the same length. Adjust the rectangle above to create a square. It is also a special case of a parallelogram but with extra limitation that the angles are fixed at 90Â°. See Parallelogram definition and adjust the parallelogram to create a rectangle.