Guess the letter in one question puzzle. It's a Relic [closed]

I am thinking of one of the following five letters

R

E

L

I

C

You can ask me one question to guess which letter it is.

Rules

No question related to the number of the letter in the alphabet order, like

" If the letters A to Z go from 1 to 26, what is the number of the letter you are thinking?" Or anything that relates to that order

No compound questions that may contain "and" "or". No multiple questions disguised as single questions.

No obvious questions like "what letter are you thinking or what words begin with your letter etc"

I am reasonably knowledgeable but am allowed to ask for clarification of your question or check it to be sure

closed as too broad by El-Guest, Chowzen, Deusovi♦Oct 21 '18 at 19:51

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

On a

16-segment display,

how many

segments are used?

How many capital cities of countries begin with your letter?
R: 6
E: 0
L: 10
I: 1
C: 7

I must be missing something quite significant, since

"Which letter are you thinking of?"

seems like a pretty straightforward question for figuring out the answer.

• Since you posted this answer, a rule has been added to prohibit that; it's retrospectively correct though. – EKons Oct 21 '18 at 19:03

After turning the letters upside-down what is the sum of the angles of the outward pointing vectors? (where N=0°, E=90°, S=180°, W=270°)
R → 0° + 315° = 315°
E → 270° + 270° + 270° = 810°
L → 180° + 270° = 450°
I → 0° + 180° = 180°1
C → 225° + 315° = 540°

1 For a barred I this is 720° (90° + 270° + 90° + 270°)