Answer: 12 3/8
10 1/2 + 10 1/2= 21
45 3/4 - 21 = 24 3/4
24 ÷ 2 = 12
Change the 3/4 into 8ths = 6/8
Divide that in half which gives you 3/8
So the length is 12 3/8
Step-by-step explanation: Undefined slope is the a vertical line The x-coordinate never changes no matter what the y-coordinate which means there no run .