Math Triangle Missing Number Triangle

1
2
3
4
5
6
7
8
9

Place the numbers 1, 2, 3, 4, 5, 6, 7, 8 and 9 in the circles so that the numbers on each side of the triangle make the same sum.

What is the sum on each side?

Challenge: How many different ways can you make this work?

The figure shows triangle def and line segment bc, which is parallel to ef: triangle def has a point b on side de and point c on side df. the line bc is parallel to the line ef. part a: is triangle def similar to triangle dbc? explain using what you know about triangle similarity. part b: which line segment on triangle dbc corresponds to line segment ef? explain your answer. part c: which angle on triangle dbc corresponds to angle f? explain your answer. asap