Answer:

Step-by-step explanation:
Let points D, E and F have coordinates
and 
1. Midpoint M of segment DF has coordinates

2. Midpoint N of segment EF has coordinates

3. By the triangle midline theorem, midline MN is parallel to the side DE of the triangle DEF, then points M and N are endpoints of the midsegment for DEF that is parallel to DE.
No the answer is 9 because 54 divided by 9 is 9
Last one D
Step-by-step explanation:
Answer:
She can fit 8 photos in a row if there are no spaces between the photos.
Step-by-step explanation:
Answer:
The answer is C. 3x+y=7, 6x+2y=10
Step-by-step explanation: