Chapter 4.7, Problem 66SR

To determine

Estimate the area of the floor of the building.

Answer to Problem 66SR

  $20sq.units.$

Explanation of Solution

Given information:

  $3$ corners of a building are partially unearthed at $\left(-1,6\right),\left(4,5\right)and\left(-1,-2\right).$

Each square grid measures $1sq.foot.$

Calculation:

Area of a triangle is

  $\frac{1}{2}\times B\times H$

Here, $B$ is the base of the triangle and $H$ is the height of the triangle.

On plotting the points representing the corners of the building, we can get the graph as follows

In the graph of the triangle, the measurement of one square is $1sq.foot$

Thus, the height of a triangle $AB$ is $5$ and the base of a triangle is $8$ .

So, area of the floor is equal to the area of a triangle,

  $\begin{array}{l}\frac{1}{2}\times B\times H=\frac{1}{2}\times 8\times 5\\ =5\times 4\\ =20\end{array}$

Hence, the area of the floor is $20sq.units.$