Plane Geometry Test Topics

The questions in the Plane Geometry Diagnostic Test are typical of those on
the Math 1 test. They range from segments, to polygons (especially triangles),
to circles and multiple figures. In this chapter we’ll use these questions to
review the plane geometry you’re expected to know. We will also use these
questions to demonstrate some effective problem-solving techniques,
alternative methods, and test-taking strategies that apply to geometry
questions.

ADDING AND SUBTRACTING SEGMENT LENGTHS

The simplest type of plane geometry questions you may encounter are like
Example 1, which involves adding and subtracting segment lengths. It’s
typical of the Math 1 test that the lengths you have to add and subtract are
algebraic expressions rather than numbers.

Example 1

Figure  1

In  Figure  1,  the length  of      is  2x  +   12, and the length  of      is  6x  –

10. If R is the midpoint of what is the length of ?

1.