You haven't provided the steps.
mathisfun.com/geometry/construct-linebisect.html
Here is a useful link to the correct steps. The instructions may not be exactly the same but I think you can do it.
Answer:
The value of radius is 7.5 units
Step-by-step explanation:
Given that a line that pass through the origin and form a triangle is a right-angle triangle. So in order to find the diameter/hypotenuse, you have to use Pythogaras Theorem :

Let a = 12 units,
Let b = 9 units,
Let c = hypo.,




We have found out that the hypotenuse of the triangle is the diameter of circle. So in order to find radius, you have to divide it by 2 :



Answer:
m < 49/12
Step-by-step explanation:
The portion of the quadratic formula under the square root sign is the discriminant.
If the discriminant is > 0 then there are two real roots.
b² -4ac > 0
-----------------------------
7² - 4(3)m > 0
49 - 12m > 0
Subtract 49 from both sides
-12m > -49
Divide both sides by -12
(when multiplying or dividing by a negative the inequality must be reversed)
m < 49/12