Answer:
The area of the neighborhood in which they are advertising is 8.75 km²
Step-by-step explanation:
The coordinates of the street corners are;
(3, 15), (6, 4) and (11,9)
Therefore;
The distance between each street corner are found using the following formula;
[tex]Distance, \ d=\sqrt{\left (y_{2}-y_{1} \right )^{2}+\left (x_{2}-x_{1} \right )^{2}}[/tex]
Substituting, using an online tool, we find the distances;
Between (3, 15) and (6, 4), d = √32.5 km
Between (6, 4) and (11,9), d = √12.5 km
Between (3, 15) and (11,9), d = 5 km
The area is given by Heron's formula as follows;
[tex]A = \sqrt{s\cdot \left (s-a \right )\cdot \left (s-b \right ) \cdot \left ( s-c \right )}[/tex]
Where;
s = (√32.5 + √12.5 + 5)/2
a = √32.5
b = √12.5
c = 5
Substituting (using an online tool) the values gives;
A = 8.75 km²
The area of the neighborhood in which they are advertising is 8.75 km²