How to count players in a certain team?

Terrorists = game.Teams.Terrorist:GetChildren()
    NumTerrorist = 0--I m stuck  here
    C4 = game.ReplicatedStorage.C4Bomb:clone()
    C4.Parent = math.random(1,NumTerrorists).Backpack
    if NumTerrorist ~= nil then
        C4:Remove()
    end

i want NumTerrorist to be the number of player in team of Terrorists and i m unsure how to count