Check the picture below.
keeping in mind that the point of tangency for a radius line and a tangent is alway a right-angle, since the "red" chord is parallel to the "green" tangent line outside, then the chord is cutting the "green" radius there in two equal halves at a right-angle, as you see in the picture.
we know the chord is 10 units long, so 5 + 5, since is perpendicularity with the radius will also cut the chord in two equal halves.
anyhow, all that said, we end up with triangle you see on the right-hand-side, and then we can just use the pythagorean theorem.

Answer: 
Step-by-step explanation:
Since Gloria cannot pay for each minute talked but for packages of 200 minutes at the rate of $25 each, we have to make calculations according to these conditions as follows:
Month 1:
Gloria talked on her cell phone for
. So, she had to buy 2 packages of
for
each package.
Hence:

Month 2:
Gloria talked on her cell phone for
. So, she had to buy again 2 packages of
for
each package.
Hence:

Month 3:
Gloria talked on her cell phone for
. So, she had to buy 3 packages of
for
each package.
Hence:

Then, if we take the total Gloria had to pay for the frist three months, we have:

The slope is the number in front of the x. In this equation it is 1.
X is something you could factor out or 4x
Answer: Option 4
Step-by-step explanation:
(linear pair)
(angle sum in a triangle)
(linear pair)