Quantitative Comparison Problems on the GRE — Geometry
On the GRE Math test, Quantitative Comparison problems cover a wide range of subjects. For example, a geometry question might require you to work with circles, rectangles, triangles, cylinders, or cubes.
In a Quantitative Comparison question, the problem lists Quantity A and Quantity B, which can be numbers, variables, equations, words, figures, and so on. Your job is to compare these two quantities and determine whether one is greater, they’re equal, or the relationship can’t be determined.
The following practice questions ask you to compare angles in a triangle and a quadrilateral.
Practice questions

AC > CB > AB. Which quantity is greater?
A: b
B: a
A. Quantity A is greater.
B. Quantity B is greater.
C. The quantities are equal.
D. It cannot be determined from the information given.

ABCD is a quadrilateral. Which quantity is greater?
A: Angle D
B: 55 degrees
A. Quantity A is greater.
B. Quantity B is greater.
C. The quantities are equal.
D. It cannot be determined from the information given.
Answers and explanations

A. Quantity A is greater.
The longest side of a triangle is opposite the largest angle.
Hence, b > a > c. Thus, Quantity A is greater, and Choice (A) is the correct answer.

C. The quantities are equal.
The interior angles of a quadrilateral add up to 360 degrees. We know three angles:
Their sum is:
Thus, the quantities are equal, Choice (C).