86 and 87 utilize the Pythagorean theorem. Where those tangent lines meet the circle forms a right angle. So you have a side length of 6 and a hypotenuse of 22. So the missing side length is 21.16. For 87, its the same thing, but you have the 2 legs but are missing the hypotenuse.
Answer:
r=2.5
I hope this helps
Edit: If you need anymore help I can gladly help! :)
This strategy works because if you subtract one number from another the sum of the two numbers should be the that is being subtracted from. (In this case, it's 200)
The is a 50% chance of being a boy or a girl.....previous siblings do not matter. Every child is an independent event. So even if u had 2 siblings that were boys, the result of the next one being a boy is still gonna be 50%...just as the odds of it being a girl, is 50% as well.
