103+53=156
156/2=78
The average or mean is 78
Let

using a graph tool
see the attached figure
The figure is a triangle
we know that
<u>The Heron's Formula</u> is a method for calculating the area of a triangle when you know the lengths of all three sides.
Hero's Formula is equal to

where
p is is half the perimeter of the triangle
a,b,c are the lengths of the sides of a triangle
so
Step 
<u>Find the length sides of the triangle</u>
a) <u>Find the distance AB</u>

Substitute


b) <u>Find the distance AC</u>

Substitute


c) <u>Find the distance BC</u>

Substitute


Step
<u>Find the perimeter of the triangle</u>

<u>Find the half of the perimeter </u>

Step 
<u>Find the area of the triangle</u>



therefore
<u>the answer is the option </u>
a) 1.65 mi^2.
600 becuase 90/.30= 300 and 300*2 =600
To divide 36/9 using the number line you have to jump from zero with length of 9 until reach 36, and the result will be the number of jumps.
I do the jumps by steps, but you can draw in the number line:
0. First jump from 0 to 9.
,
1. Second jump from 9 to 9+9=18.
,
2. Third jump from 18 to 18+9=27.
,
3. Fourth jump from 27 to 27+9=36.
,
4. Great!! We already reach 36.
So, we need four jumps of 9 to reach 36 from 0.
So, the result is 36/9=4