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.
The equation looks like this:
26=x*3.5+8.50
where x is the number of pen you bought.
We solve it like this:
first, we subtract 8.50 from both sides:
17.50 =3.5*x
now we divide both sides by 3.5:
5=x
so you purchased 5 pens.
Answer:
49
Step-by-step explanation:
When Karen was born, the dad is 22 so Karen is now 27 which means the dad is 22+27= 49
Answer:

Step-by-step explanation:


Thus,
