Use the pythagorean theorem to find the diagonal.
25+144=169, sqrt(169)=13, so the diagonal (OR) is 13.
The opposite sides of a rectangle are congruent. OA=5, AR=12
Let's find PO.
So, OA=PO*OR
Fill in known values.
52=PO*13.
Make PO the variable x.
25=13x
Divide by 13 on both sides.
x=25/13
25/13 = 1.9230769230769231
Round to the nearest hundredth.
x≈1.92
13-1.92 = 11.08, so the second part (PR) is 11.08
Now, to find PA we need to do the square root of 11.08*1.92.
11.08*1.92 = 21.2736, or 21.27
sqrt(21.27) = 4.6119410230400822, or approximately 4.61.
Thanks, rarinstraw.......here is a slightly different approach.....
tan(BOR) = 5/12 ....so
arctan(5/12) = BOR = about 22.62°
Then, because BOA is a right angle, POA = [90 - 22.62]° = 67.38°
So
sin (POA) = PA / OA
sin (POA) = PA / 5
5 sin[67.38 ] = PA = about 4.615 units = 4.62 [ rounded]