document.write( "Question 337062: Points P, Q, and R lie in a plane. If the distance between P and Q is 5 and the distance between Q and R is 2, which of the following could be the distance between P and R ?
\n" ); document.write( "I. 3
\n" ); document.write( "II. 5
\n" ); document.write( "III. 7
\n" ); document.write( "(A) I only
\n" ); document.write( "(B) II only
\n" ); document.write( "(C) III only
\n" ); document.write( "(D) I and III only
\n" ); document.write( "(E) I, II, and III
\n" ); document.write( "
\n" ); document.write( "

Algebra.Com's Answer #241678 by CharlesG2(834)\"\" \"About 
You can put this solution on YOUR website!
Points P, Q, and R lie in a plane. If the distance between P and Q is 5 and the distance between Q and R is 2, which of the following could be the distance between P and R ?
\n" ); document.write( "I. 3
\n" ); document.write( "II. 5
\n" ); document.write( "III. 7
\n" ); document.write( "(A) I only
\n" ); document.write( "(B) II only
\n" ); document.write( "(C) III only
\n" ); document.write( "(D) I and III only
\n" ); document.write( "(E) I, II, and III\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "distance PQ is the length of line PQ, distance QR is the length of line QR
\n" ); document.write( "distance PR is the length of line PR and is unknown
\n" ); document.write( "line PQ has length 5, line QR has length 2, line PR has length ?\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "these 3 lines form a triangle
\n" ); document.write( "PR has to be between the difference of PQ and QR AND the sum of PQ and QR, due to the Triangle Inequality Theorem (part of the properties of triangles)
\n" ); document.write( "PQ - QR = 5 - 2 = 3
\n" ); document.write( "PQ + QR = 5 + 2 = 7\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "3 < PR < 7
\n" ); document.write( "PR can not be 3 and PR can not be 7, UNLESS points are collinear (in a straight line)\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "(B) II only is answer, well if the 3 points are not collinear (in a straight line)\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "so answer is (E) I, II, and III\r
\n" ); document.write( "\n" ); document.write( "BUT case I and case III can only occur if the points are collinear\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );