3 Tips to Prepare for ACT Geometry Questions

The ACT math test covers three main content areas: Preparing for Higher Math, Integrating Essential Skills and Modeling. For some high school students, geometry is one of the hardest question types on the test.

Unlike the SAT, the ACT does not provide a formula sheet – meaning students must largely work off of their existing knowledge. Students should be aware that geometry can have a noticeable impact on their score, as it accounts for 12-15 percent of the grade on the Preparing for Higher Math content category.

Here are three geometry prep strategies that test-takers can implement during their ACT review.

[Read: How to Evaluate ACT, SAT Math Before Choosing an Exam.]

Begin with coordinate and plane geometry. Consider reviewing coordinate geometry topics like slope first. As some of these concepts are related to algebra, this may be a more familiar first step for students. Students should be prepared to work with lines graphically, on their calculators and algebraically.

Next, students should review the basic terms and important details concerning angles and the components of basic shapes.

Students who are not familiar with terms like "congruent" should spend some time reviewing definitions, as not knowing keywords on a geometry question can make it hard to navigate the problem. Ensure you can define supplementary and complementary angles, interior angles, the Pythagorean theorem and the degrees in a triangle.

One great way to study is to review proofs. This can help students remind themselves of what they need to know to deduce unstated information in triangles and other shapes. Some of the terms listed in proofs will be completely known, some will be vaguely familiar and some will be forgotten. This should help you identify which subjects need additional light review versus heavy study.

[Read: Master Common Geometry for Competitive SAT Math Score.]

Memorize key formulas. There are a number of geometry formulas that ACT test-takers must memorize, which can make studying for this portion of the exam even more challenging.

While you may feel intimidated by the amount of material you need to learn, remember that starting your preparation early is critical. Divide the formulas by shape and master them in groups, such as all circle formulas or all triangle formulas.

Students should also consider when it is important to memorize a formula versus learn a concept. One of the best examples of this distinction involves calculating perimeter, or the distance around a two-dimensional object.

You could memorize the perimeter formulas for rectangles, squares and triangles, or you could recognize that you simply need to add together the lengths of each side, no matter the shape. This reduces the number of formulas to memorize and ensures that you are ready for any perimeter question.

The one exception to this is circumference, which is the perimeter of a circle. Memorize this formula, and be prepared to potentially use it alongside other circle formulas.

[Read: Improve Interpretation of Visuals for ACT Math, Science Success.]

Students may struggle to recall all of the surface area formulas, and surface area problems on the ACT can involve irregular shapes. So it is important to understand that surface area can be determined by adding together the area of each face on an object.

Some students may benefit from thinking of surface area as trying to wrap a gift – think in terms of how much wrapping paper it would take to cover the entire surface of an object.

Finally, students can benefit greatly from memorizing Pythagorean triplets and the formulas for 45-45-90 and 30-60-90 triangles.

Recognize that solid geometry is least frequently assessed. While it is wise to review solid geometry as time permits, do not prioritize it above other geometry concepts.

If you encounter a surface area problem, remember the advice above. For volume, there is one important rule that can help students: If a shape is uniform from base to top – meaning it is not tapered like a cone or pyramid – the volume is the area of the base times the height.

When studying solid geometry, review these terms: edge, face, side, surface area, vertex and volume.

An organized plan of attack is essential when preparing for the geometry portion of the ACT math test. Because harder geometry concepts are built upon the most basic, students should have a strong grasp of the fundamentals to do well.

Students also need to set aside ample time for memorizing equations and recognizing when a formula should be used. However, if you begin to study well in advance of the ACT and break down geometry by subject area, you will be on your way to a competitive score.