Final answer:
The length of MN in a rectangle LMNO can be found by subtracting the length of one side from the total length of the rectangle.
Step-by-step explanation:
To find the length of MN, we need to analyze the properties of a rectangle. In a rectangle, opposite sides are equal in length. Since LMNO is a rectangle, that means LM is equal to NO. So, to find MN, we can subtract either LM or NO from the total length of the rectangle. Let's say the total length of the rectangle is 27. If we subtract LM (which is equal to NO) from 27, we get 27 - 10 = 17. Therefore, the length of MN is 17. So the correct answer is option D, 17.