Reading the question carefully, "<span>He draws the diameter of the circle through center P using a straight edge. Next he opens his compass to a width equivalent to the radius of the circle." - that implies that Mateo is still in the process of drawing the circle by which the equilateral is inscribed to.
The next steps should be:
*He should draw the upper and lower arcs using the compass opened to a width equivalent to the radius of the sircle.
*Make a vertical diameter using centroid P as basis.
*Draw two right triangles facing the opposite directions using the top most point by which the vertical diameter of the circle touches the top most circumference of the circle.
Doing these steps, Mateo will be able to draw an equilateral triangle inscribed in a circle.
</span>
Step-by-step explanation:
We have got the lines :

Both lines intercept the x-axis in the point :

In all point from x-axis the y-component is equal to 0.

We replace the I point in the lines equations:

From the first equation :

From the second equation :

Then 
Finally :

y = ax + b and y = cx + d have the same x-intercept ⇔ad=bc
Answer:
$190.50
Step-by-step explanation:
Expected value is the sum of each possible income multiplied by its probability.
There's a 5% chance that the vendor makes $200 and loses $190 (net gain of $10).
There's a 95% chance that the vendor makes $200 and loses $0 (net gain of $200).
So the expected value is:
Exp(RS) = $10 × 0.05 + $200 × 0.95
Exp(RS) = $190.50
The answer is 6 centimeters