## Definition Of Formula

A Formula is an expression or equation that expresses the relationship between certain quantities.

For Example, A = pr2 is the formula to find the area of a circle of radius r units.

From this formula, we can know the relationship between the radius and the area of a circle. The area of a circle varies directly as the square of its radius. Here p is the constant of variation.

A. 64 ft/sec
B. 128 ft/sec
C. 16 ft/sec
D. 32 ft/sec