In mathematical terms, an oval -- a shape that looks like a lengthened or squashed circle -- is called an ellipse. This means you can use the area formula for an ellipse to find an oval's area. The area of an ellipse is based on the length of the longest and shortest axes that pass through its center.
The Axes of an Ellipse
The axis of an ellipse is a line that passes through the ellipse's center and connects two points on opposite sides of the ellipse's edge. An ellipse's major axis is the longest axis of the ellipse. In other words, it measures the longest length of the ellipse. The minor axis is the shortest axis of the ellipse. The minor axis of the ellipse will always be perpendicular to the major axis. If you draw both the minor and major axis inside an ellipse, they will form a cross shape. You can think of the major and minor axis of an ellipse as the ellipse's length and width.
Area of an Ellipse
The area of an ellipse can be calculated by multiplying the length of the major axis by the length of the minor axis, then multiplying by pi. Pi is a constant used in equations involving circles, and is always equal to the same value -- approximately 3.14 -- though it can be extended to an infinite number of decimal places. So the formula for ellipse area is A = pi x major axis x minor axis.
Take a silver platter with length of 10 inches, and width of 6 inches. The length will be the major axis of the platter, and the width the minor axis. To find area, multiply these lengths by pi: A = 3.14 x 10 inches x 6 inches = 188.4 square inches.