For two line segments to be parallel, their slopes must be equal.
Therefore slope of AB must be equal to slope of CD
which is, option 3
<span> (y4-y3)/(x4-x3)=(y2-y1)/(x2-x1)</span>
A circumscribed angle is that which is formed by the intersection of the two tangent lines in a circle. With this, we can conclude that segments AC and AB are tangent to circle O. The tangent lines forms a right angle with the radius of the circle drawn from the center of the circle to the tangent point.
By the explanation above, we can say that angles C and B are equal to 90° and that triangle ACO and triangle ABO are congruent. Which means that segment AC is equal to segment AB. Thus, the length of AB is also 4.
<em>Answer: 4 units</em>
Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions.
Below are the answers:
<span>7. C. H(n) = ½n^2 + n + 1
</span>8. D. As the number of rows increases, the hexagonal rig gets closer to having twice as many lights as the square rig.