Have you seen these things being asked in OG or actual test?

[towerSpider]

Area of sphere, or cone . Surface area of sphere or cone, etc. I can not think of anything else but sometimes i see guides teaching weird things that i see never on tests of kaplan, gmatprep, etc.

[towerSpider]

Like questions on area of trapezoid, etc.

[Brian@VeritasPrep]

Hey TowerSpider,

You're not specifically responsible for those concepts and formulas, but the GMAT could test them in a few ways:

1) Supply you with the formula for that particular shape (there are at least a few old OG problem that gave the formula for volume of a sphere)

2) Use that shape but only test you on something for which you are responsible (say, the areas of cross sections of two circles that are part of the same cone or sphere)

Accordingly, don't worry about memorizing formulas for spheres/cones/pyramids, but don't be completely surprised if you see such a shape on the exam - if that comes up, remember that they're testing you on something that you DO know, and so focus on those skills that you have at your disposal to better solve the problem.