Bunuel wrote:
If A is the center of the circle shown above and AB = BC = CD, what is the value of x ?
A. 15
B. 30
C. 45
D. 60
E. 75
PS21278
Since all of the radii in a circle have the same length, we know that the 3 red lines below all have the same length.
Since we are told that AB = BC = CD, we can say that all 5 red lines below have the same length
This means the two red triangles must be
equilateral triangles, which means all of their angles are 60°
Since all 4 sides of the red quadrilateral below have the same length, we know that the quadrilateral is a
rhombusIn a rhombus, the diagonals bisect the angles.
So the blue diagonal above, bisects the
60° angle into two equal angles of 30° each, which means
x = 30Answer: B
Cheers,
Brent
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Brent Hanneson – Creator of gmatprepnow.com
I’ve spent the last 20 years helping students overcome their difficulties with GMAT math, and the biggest thing I’ve learned is…
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