Difference between revisions of "1959 AHSME Problems/Problem 31"

(created solution page)
 
(diagram)
Line 4: Line 4:
  
 
== Solution ==
 
== Solution ==
 +
 +
<asy>
 +
 +
import geometry;
 +
 +
point O=(0,0);
 +
real r=5*sqrt(2);
 +
point A=(-r/sqrt(5),2r/sqrt(5));
 +
point B=(-r/sqrt(5),0);
 +
point C=(5,5);
 +
point D=-C;
 +
 +
markscalefactor=0.1;
 +
 +
dot(O);
 +
label("O",O,S);
 +
 +
// Circle with diameter
 +
draw(circle(O,r));
 +
draw((-r,0)--(r,0));
 +
 +
// Small square
 +
draw((-r/sqrt(5),2r/sqrt(5))--(-r/sqrt(5),0)--(r/sqrt(5),0)--(r/sqrt(5),2r/sqrt(5))--(-r/sqrt(5),2r/sqrt(5)));
 +
dot(A);
 +
label("A",A,NW);
 +
dot(B);
 +
label("B",B,SW);
 +
draw(O--A);
 +
draw(rightanglemark(A,B,O));
 +
 +
// Big Square
 +
draw((5,5)--(5,-5)--(-5,-5)--(-5,5)--(5,5));
 +
dot(C);
 +
label("C",C,NE);
 +
dot(D);
 +
label("D",D,SW);
 +
draw(C--D);
 +
 +
</asy>
 +
 
<math>\fbox{B}</math>
 
<math>\fbox{B}</math>
  

Revision as of 20:16, 20 July 2024

Problem

A square, with an area of $40$, is inscribed in a semicircle. The area of a square that could be inscribed in the entire circle with the same radius, is: $\textbf{(A)}\ 80 \qquad\textbf{(B)}\ 100\qquad\textbf{(C)}\ 120\qquad\textbf{(D)}\ 160\qquad\textbf{(E)}\ 200$

Solution

[asy]  import geometry;  point O=(0,0); real r=5*sqrt(2); point A=(-r/sqrt(5),2r/sqrt(5)); point B=(-r/sqrt(5),0); point C=(5,5); point D=-C;  markscalefactor=0.1;  dot(O); label("O",O,S);  // Circle with diameter draw(circle(O,r)); draw((-r,0)--(r,0));  // Small square draw((-r/sqrt(5),2r/sqrt(5))--(-r/sqrt(5),0)--(r/sqrt(5),0)--(r/sqrt(5),2r/sqrt(5))--(-r/sqrt(5),2r/sqrt(5))); dot(A); label("A",A,NW); dot(B); label("B",B,SW); draw(O--A); draw(rightanglemark(A,B,O));  // Big Square draw((5,5)--(5,-5)--(-5,-5)--(-5,5)--(5,5)); dot(C); label("C",C,NE); dot(D); label("D",D,SW); draw(C--D);  [/asy]

$\fbox{B}$

See also

1959 AHSC (ProblemsAnswer KeyResources)
Preceded by
Problem 30
Followed by
Problem 32
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 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
All AHSME Problems and Solutions

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