The letter W is between V and X.
W
The 7 letters on the lower row areZ X C V B N Mso answer is V letter
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern ---V--X. That is, seven letter words with 4th letter V and 7th letter X. In alphabetical order, they are: gravlax
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 3 words with the pattern -V----X. That is, seven letter words with 2nd letter V and 7th letter X. In alphabetical order, they are: overlax overmix overtax
the letter A, the letter V, the letter X is the best example. If by perpendicular you mean 90º, the answer is E, F, I, L, and T. A, V and X are not perpendicular, they are acute angles.
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern V-X--IS-. That is, eight letter words with 1st letter V and 3rd letter X and 6th letter I and 7th letter S. In alphabetical order, they are: vixenish
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern V--R--X. That is, seven letter words with 1st letter V and 4th letter R and 7th letter X. In alphabetical order, they are: vitraux
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern -V--T-X. That is, seven letter words with 2nd letter V and 5th letter T and 7th letter X. In alphabetical order, they are: overtax
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern -L-X-V-. That is, seven letter words with 2nd letter L and 4th letter X and 6th letter V. In alphabetical order, they are: fluxive
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 2 words with the pattern F-X---V-. That is, eight letter words with 1st letter F and 3rd letter X and 7th letter V. In alphabetical order, they are: fixative foxglove
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern V---R-X. That is, seven letter words with 1st letter V and 5th letter R and 7th letter X. In alphabetical order, they are: victrix
According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 1 words with the pattern -X-L-V-. That is, seven letter words with 2nd letter X and 4th letter L and 6th letter V. In alphabetical order, they are: exclave