The radius is 4.99, im sure
Answer:

Step-by-step explanation:
Number of students participating in the competition = 13.
Total number of students in the school = 15.
Thus ,
the number of students who did not make to this competition =
Total number of students - number of students participated
= 15-13 = 2.
Now ,
probability of the student who do not makes it to the competition
= fraction of students who did not make to this competition from the total number of students .
=
.
A straight angle is 180 degrees. if you bisect it (cut it in half), you'll end up with two 90 degree angles, which are called right angles.
Positive 25 that's the answer