Button appear with if statment C#

So quick question. I have an object that hits a max speed of 100. Once it hits that speed I want a button to appear. Would I just do an if statement like. If(max speed == 100)
{
//gui.button blah blah
}
Or do I have to do something different? Also how could I make an item or image appear when it hits max speed?

I wouldn’t recommend using legacy GUI but you can use it. Not the most elegant way, but that depends on how you are increasing the speed. This should give a general idea.

private bool didHitSpeedLimit = false;
private float speed = 10f;

public void ChangeSpeed(float delta){
speed+=delta;
didHitSpeedLimit = (speed >= 100f) ? true:false;
}

//If using new uGUI
void Update(){
if(didHitSpeedLimit){
//Enable new uGUI button
}
}

//If using old uGUI
void OnGUI(){
//Show your button code.
}