Use the Pythagorean theorem to solve this problem. So, 81+x^2=1681. ( Pythagorean theorem: a^2+b^2=c^2). x^2=1600. x=40.
Answer:
-2
Step-by-step explanation:
Assuming the typewriter-looking words are the line names...
1. Line R
2. Line Q (Or R, but it is most likely Q)
3. Points E and F
Collinear Meaning: http://mathworld.wolfram.com/Collinear.html