Trapezium rule- underestimate/ overestimate

whether it is always an overestimate when the curve is concave and always an underestimate when the curve is convex ?

When the lines go over the curve (Usually happens in concave curves) it's an overestimate because it includes that small area above the curve.

When the lines dont go over the curve (Usually happens when its a convex curve) its an underestimate because it misses a small area of the curve out.

I think this is right, hopefully someone can confirm.

Hope this helps.