Cho Dan: A man, a plan, a canal, Uraguay. Registered: Before you were born. Location: St. Petersburg, FL Posts: 1,000,000

Ah hem...clearly the slope of the green triangle is 2/5 while the slope of the red triangle is 3/8. Hence the first example is concave while the second is convex and the hole is accounted for. ( I win!) Hey! Where's the salt shaker?