Question

How can I show “√” (tick symbol) in label text?

Answer 1

This code will do it for you:

LblTick.Text  = ((char)0x221A).ToString();

Edit:

or even easier:

lblTick.Text = "\u221A";

Edit 2:

And, as pointed out in a comment, that code (221A) is actually a square root symbol, not a tick.
To use the true tick mark, you can use the following:

lblTick.Text = "\u2713";

or for a heavy tick mark, you can use the following (but you may get font issues with this one):

lblTick.Text = "\u2714";

(Credit to @Joey for that comment!)