That's a right triangle. I didn't tell you to imagine a right triangle. I told you to imagine a triangle in general.
That's isosceles. You have to try again. We're not after particular angles or sides here. Try to be blind to those. Only see triangles as they are beyond these differences.
You being deliberately obtuse?
Now, if this were just satire of the real world instead of open criticism and I were writing for The Big City Review of Triangle Depictions I'd probably tell you, "Finally, ecce triangulus! This here is the naked triangle condition that shines through in every triangle ever drawn!"
But this here is just an equilateral triangle. It's not The Triangle, because well, there's no such thing. You cannot imagine an abstract triangle. You'll always imagine a particular one, be it isosceles or scalene. And when you draw a triangle, you'll draw a particular one and everything you want to show about triangles in general will have to be done through that particular shape. There's no escaping these differences. Representation - in your mind or on paper - is by definition of particulars. Keeping to equilateral triangles your whole life won't change that fact. It won't bring you closer to the ideal triangle. It will, if anything, distort and narrow your idea of what a triangle must be.
And if your mind cannot do more than this for 3 sticks put together, why would you think it can do it for a concept as complex as "human being"?