M7MBA wrote:
In the diagram above, line \(PQ\) is tangent to the circle, and the measure of arc \(PR\) is \(70°.\) What is the measure of \(∠PQR?\)
A. \(15°\)
B. \(20°\)
C. \(25°\)
D. \(30°\)
E. \(35°\)
[spoiler]OA=B[/spoiler]
Source: Magoosh
While we are not told that it is so, we assume that O is the center because otherwise, the answer cannot be determined from the given information.
Since arc PR = 70 degrees, then the intercepted central angle (angle ROP) is also 70 degrees. Furthermore, since line PQ is tangent to the circle, angle OPQ = 90 degrees. Therefore, angle PQR = 180 - 70 - 90 = 20 degrees.
Answer: B
Scott Woodbury-Stewart
Founder and CEO
[email protected]
See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

