It depends on the font. Using this font, I count 8 upper case letters:
E F H I M N W Z
and 2 Lower case letters:
w z
In the English alphabet, the uppercase letters that have perpendicular line segments are A, B, D, E, F, H, K, L, T, and Z. This totals to 10 uppercase letters. Each of these letters includes at least one pair of line segments that meet at a right angle.
25 o because sOme of them are perpendicular
I
In the case of upper case letters in the Roman alphabet, and allowing tine segments of lines that are curved, they are: B, C, D, E, F, G, H, M, N, O, P, Q, R, S, U, Z.
None in the Roman alphabet.
The letter - H
In the upper case Roman alphabet they are: C, I, J, O and S. However, in the case of C, O and S, there are parts of the curved segments which are parallel.
In the English alphabet, the uppercase letters that have perpendicular line segments are A, B, D, E, F, H, K, L, T, and Z. This totals to 10 uppercase letters. Each of these letters includes at least one pair of line segments that meet at a right angle.
25 o because sOme of them are perpendicular
I
E
Letters that have parallel line segments are H, E, F, M, and N
The alphabet has 26 letters. The letter "D" comes after the letter "C".The English alphabet, in order:ABCDEFGHIJKLMNOPQRSTUVWXYZ
The English language alphabet has 26 letters.
W
t
There are 26 letters in the English alphabet.