Question

A long oval is shown. Two lines are drawn where the sides are straight to form right angles.
How can you decompose the composite figure to determine its area?

as two semicircles and a rectangle
as two circles and a rectangle
as a circle and a square
as two semicircles and a trapezoid

Answer 1

Answer: as two semicircles and a rectangle.

Reason: the "long oval" can be seen as a central rectangle (between the straight sides) with a semicircle attached to each short end. The two semicircles together make one whole circle, so the total area is

Area = (area of rectangle) + (area of circle)
= (length L × diameter d) + π(r^2) with r = d/2
= L·d + πd^2/4.

The other choices are wrong because the shape does not contain two full circles, nor a square, nor a trapezoid.