The area enclosed within the curve $|x| + |y| = 1$ is

$P(2, 1), Q(4, -1), R(3, 2)$ are the vertices of a triangle. If lines parallel to the opposite sides are drawn through $P$ and $R$ to intersect at $S$,then the area of $PQRS$ is:

$OPQR$ is a square and point $Q$ is $(\alpha, \alpha)$. If $M$ and $N$ are the midpoints of sides $PQ$ and $QR$ respectively,then what is the ratio of the area of the square to the area of triangle $OMN$?

The area (in square units) of the triangle formed by the points with polar coordinates $(1, 0)$,$(2, \frac{\pi}{3})$,and $(3, \frac{2\pi}{3})$ is:

If $(0, 0), (1, 2),$ and $(-3, 4)$ are the midpoints of the sides of a triangle $ABC$,find the area of triangle $ABC$.

$A$ rectangle is divided into $16$ sub-rectangles as shown in the figure. The number in each sub-rectangle represents its area. What is the area of the rectangle $KLMN$?