Let PQR be an equilateral triangle, centered at O. A point X is chosen at random inside the triangle. Find the probability that X is closer to O than to any of the sides. (In other words, find the probability that XO is shorter than XA, XB, and XC.)
See the following
I've labeled the center of equilateral triangle XYZ as A
Any point inside equilateral triangle DEF will be closer to A than to any of the sides of XYZ
Each side DEF is 1/2 the length of a side of XYZ.....so the area of DEF = (1/2)^2 [XYZ] = (1/4) [XYZ]
So the probability is (1/4)