Difference between revisions of "2017 AMC 12A Problems/Problem 16"

Line 19: Line 19:
 
\qquad\textbf{(D)}\ \frac{5}{8}\sqrt{2}
 
\qquad\textbf{(D)}\ \frac{5}{8}\sqrt{2}
 
\qquad\textbf{(E)}\ \frac{11}{12} </math>
 
\qquad\textbf{(E)}\ \frac{11}{12} </math>
 +
 +
==Solution==
 +
 +
==See Also==
 +
{{AMC12 box|year=2017|ab=A|num-b=15|num-a=17}}
 +
{{MAA Notice}}

Revision as of 18:52, 8 February 2017

Problem

In the figure below, semicircles with centers at $A$ and $B$ and with radii 2 and 1, respectively, are drawn in the interior of, and sharing bases with, a semicircle with diameter $JK$. The two smaller semicircles are externally tangent to each other and internally tangent to the largest semicircle. A circle centered at $P$ is drawn externally tangent to the two smaller semicircles and internally tangent to the largest semicircle. What is the radius of the circle centered at $P$?

[asy] size(5cm); draw(arc((0,0),3,0,180)); draw(arc((2,0),1,0,180)); draw(arc((-1,0),2,0,180)); draw((-3,0)--(3,0)); pair P = (-1,0)+(2+6/7)*dir(36.86989); draw(circle(P,6/7)); dot((-1,0)); dot((2,0)); dot(P); [/asy]

$\textbf{(A)}\ \frac{3}{4} \qquad \textbf{(B)}\ \frac{6}{7} \qquad\textbf{(C)}\ \frac{1}{2}\sqrt{3} \qquad\textbf{(D)}\ \frac{5}{8}\sqrt{2} \qquad\textbf{(E)}\ \frac{11}{12}$

Solution

See Also

2017 AMC 12A (ProblemsAnswer KeyResources)
Preceded by
Problem 15
Followed by
Problem 17
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
All AMC 12 Problems and Solutions

The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions. AMC logo.png