You can add the pounds together and the ounces together separetly. As long as the ounces are less than 16 (since 16 ounces=1 pound), you wont hvae to convert those ounces into pounds. So you can simply add the numbers up to get 23 pounds and 9 ounces
This is true. If the end point of the line FG line in the same plane, then all of the points on the line FG will lie on the same plane. But this is only true if the FG line is a straight line. If FG is a curved line this statement can but does not have to be true.