Answer: Here is an example.
Explanation:
Given: parallelogram ABCD, sides as marked.
Find AD.
Solution: 6x - 10 = 3x + 5 (opposite sides)
3x - 10 = 5; 3x = 15; x = 5
AD = 4x - 5 = 4(5) - 5 = 15
Remember:
• This is where the properties of a parallelogram are needed. You know the opposite sides of a parallelogram are congruent, so set the opposite sides equal to one another.
• Be sure to pair up the opposite sides correctly. The side labeled 4x - 5 will not be used when solving for x, but will be used to solve for AD.