SOLUTION: REVIEW 30: The radius of a Circle O is 4, if radii OA and OB form 90o angle, AB = ?

Question 79709: REVIEW

30: The radius of a Circle O is 4, if radii OA and OB form 90o angle, AB = ?
Answer by doctor_who(15) (Show Source): You can put this solution on YOUR website!
There are 360o in a circle, so if the angle between OA and OB is 90o then you've cut a slice exactly equal to a quarter of a circle. (because 360 = 90 X 4)
The formula for the whole circumference of the circle is pi X radius squared
.. which is pi X 4 X 4 = 16 X pi.
You've got exactly a quarter of that, so AB is 4 X pi. (ANSWER)
If you need an exact answer, work it out on a clculator, knowing that pi = 3.14159 (approximately)

RELATED QUESTIONS
Circle O has a radius of 12. Points A and B are on the circle forming radii OA and OB.... (answered by greenestamps)

IN circle O, OA and OB are radii and the measure of angle BOA eqals 120. Tangents PA and... (answered by Fombitz)

: point o, a ,b lie on the same line. oa = 12 cm, ob = 9 cam. find the distance between... (answered by greenestamps)

Points O, A, B lie on the same line. OA=12 cm, OB=9 cm. Find the distance between the... (answered by ankor@dixie-net.com)

hi , i was wondering if you can help me in writing proofs ? i've been learning the two... (answered by lynnlo)

A,B, and C are 3 points on circle. OA is a tangent at A and OBC is a straight line. If... (answered by greenestamps)

I need major help on how to answer these questions and what they are. :( this is an... (answered by Fombitz)

A circular sector AOB, centre O and radius 8 cm, contains an angle of {{{3pi/4}}} radians (answered by greenestamps)

Given the circle with center O, radius OA, diameter BC, where OA perpendicular BC, and... (answered by Edwin McCravy)