Please help! What is the area in square units?

9514 1404 393

  103 square units

Step-by-step explanation:

There is a way to find the area by counting grid points, but the fairly large number of them suggests that could be both tedious and prone to error. Instead, we'll chop up the figure into a trapezoid and two triangles.

From the top corner of the right edge draw a horizontal line across the figure. This will make the bottom portion a trapezoid and the top portion two triangles. The length of that horizontal line is 13 units, the height of the trapezoid, and the sum of the triangle bases.

The bottom trapezoid has a left-side base of 7 units and a right-side base of 6 units. Its area is ...

  A = 1/2(b1 +b2)h

  A = 1/2(7 +6)(13) = 1/2(13)(13) = 169/2 = 84.5 . . . square units.

The right top triangle has a base of 11 and a height of 3, so its area is ...

  A = 1/2bh

  A = 1/2(11)(3) = 33/2 = 16.5 . . . square units

The left top triangle has a base and height of 2 units each, so its area is ...

  A = 1/2(2)(2) = 2 . . . square units

Then the total area of the figure is ...

  84.5 +16.5 +2 = 103 . . . square units

Check

Here is the check by counting grid points. The number of grid points on the outline of the figure is i=22. The number of grid points inside the figure appears to be b=93. Then the area by Pick's theorem is ...

  b +i/2 -1 = 93 + 22/2 -1 = 103 . . . square units

20

step-by-step explanation: