[MrPaulistinha]

usa o IsPlayerInRangeOfPoint...

pawn Код:

forward Explodir();
public Explodir()
{
if(IsPlayerInRangeOfPoint(playerid, 7.0, x, y, z))
{
    new Float:x, Float:y, Float:z;
    // Create an explosion at the player's position
    CreateExplosion(x, y, z, 12, 10.0);
    return 1;
}

acho que deve esta certo... tenta compilar.

PS: usei exemplo do wiki-samp