Praxis Core Math: Geometry Practice Questions

April 8, 2016

On the Math test in Praxis Core, you’ll be asked a handful of geometry questions. While the subset of geometry questions is not the largest category on the exam, there will still be a significant number of geometry questions on test day. You can expect geometry answers to be about 15% of your final Core Math score.

So obviously you’re going to want to do well on the types of geometry questions seen in Praxis Core math. Geometry problems on this exam fall into three broad categories: coordinate plane geometry, geometry with two dimensional shapes (squares, cubes, triangles, circles, etc..), and geometry with three dimensional shapes (cylinders, cones, angular blocks, and so on). Below, you can test your Praxis Core Math geometry skills with one practice question from each category. An answer key is available at the very bottom of this post.

Practice coordinate plane geometry question

Note: I almost considered including this question type in the practice set for numbers and quantity. This is because coordinate plane geometry on the Praxis Core always boils down to addition or subtraction. However, doing these problems efficiently and correctly does require a keen sense of geometric space. So I’m going to count these as true geometry questions.

If rhombus ABCD in the xy-plane is shifted 3 units down and 5 units to the left, what would be the coordinates of point D after the shift?

A) (-3, 10)

B) (-3, 0)

C) (10, 3)

D) (0, -3)

E) (5, -3)

Practice two-dimensional geometry question

The rectangle above is four centimeters high and 8 centimeters wide. What is the approximate length of each diagonal (diagonals AC and BD)?

A) 7

B) 3

C) 9

D) 10

E) 5

Practice three-dimensional geometry question

The figure above shows a three dimensional object comprised of a cylinder with a radius of 4 feet and a height of 5 feet, topped by a right cylinder cone with a radius of 4 feet and a height of 3 feet. What is the approximate total volume of this object? (The volume of a right cylinder cone with a base radius r and height h is 1/3 pi(r^2)h.)

A) 200 cubic feet

B) 300 cubic feet

C) 335 cubic feet

D) 415 cubic feet

E) 610 cubic feet

Answer Key

Notes about the answers:

The answer to question 1 is a simple matter of correctly subtracting 3 from the y coordinate, and 5 from the x coordinate. Answer two requires you to know and correctly apply the Pythagorean theorem, which states that in a right triangle where a and b are the lengths of the sides of the right angle, and c is the length of the side opposite the right angle, a^2 + b^2 = c^2. The answer to the third question gives you the formula for the volume of a right circular cone, but it also requires you to know and use the formula for cylinder volume: V =pi(r^2)h.

Author

David Recine

David is a Test Prep Expert for Magoosh TOEFL and IELTS. Additionally, he’s helped students with TOEIC, PET, FCE, BULATS, Eiken, SAT, ACT, GRE, and GMAT. David has a BS from the University of Wisconsin-Eau Claire and an MA from the University of Wisconsin-River Falls. His work at Magoosh has been cited in many scholarly articles, his Master’s Thesis is featured on the Reading with Pictures website, and he’s presented at the WITESOL (link to PDF) and NAFSA conferences. David has taught K-12 ESL in South Korea as well as undergraduate English and MBA-level business English at American universities. He has also trained English teachers in America, Italy, and Peru. Come join David and the Magoosh team on Youtube, Facebook, and Instagram, or connect with him via LinkedIn!

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Comments

11 responses to “Praxis Core Math: Geometry Practice Questions”

Ted

July 5, 2016

The answer given for the “Practice two-dimensional geometry question” is incorrect.

Using the Pythagorean theorem:

4 squared + 8 squared = x squared
16 + 64 = 80
The correct answer should be the square root of 80: 8.944

(This is the second practice question I have completed today in which an incorrect answer was credited with being correct.)

Reply
1. David Recine
  
  July 5, 2016
  
  In this case, the answer in the post actually is correct Ted. It looks like you missed one important keyword in the problem– you’re asked to find the approximate length of each diagonal, not the exact length. 8.944 would be the correct answer (rounded to the nearest thousandth), but 9 is an acceptable whole number approximation of the square root of 80.
  
  (But great catch on the incorrect numeric entry problem over in the Practice Algebra Questions post, Ted!)
  
  Reply
  1. Lisa A Gifford
    
    December 27, 2016
    
    The answer key says “B” which is 3???
    
    Reply
    1. David Recine
      
      January 1, 2017
      
      Hi Lisa,
      
      Thanks for bringing that to my attention! The answer to the second question should actually be “C,” which is 9. I’ve just edited the blog post to get rid of the error.
      
      Reply
David G.

July 26, 2016

Can you explain the third problem? I come up with 80 pi plus 16 pi which gives me an approximate value of 301

Reply
1. David Recine
  
  August 1, 2016
  
  NOTE: Edited to correct a math mistake!
  
  To David G, and Fee, the commenter below— You are absolutely correct, and my original answer was wrong! The formula for the right cone is 1/3 π(r^2)h . Height is 3 and radius is 4. Plug in those numbers, and you get (1/3)*π*(4^2)*3. (1/3)*3 is 1, so the 1/3 and the 3 cancel each other out, for just 16π. 16π is roughly 50, and 80π is roughly 251. So your calculation of 301 is right, and the approximate answer should actually be B.
  
  Reply
  1. fee
    
    August 17, 2016
    
    wouldn’t you use the height of the right cone which is 3ft instead of the height of the cylinder when finding the total volume of the cone?
    
    Reply
    1. David Recine
      
      August 22, 2016
      
      You’re right, Fee! Thanks for bringing this to my attention! I’ve edited my original response to David G, and edited the post to reflect the correct answer, which is actually (B) and not (C).
      
      Reply
  2. Tierra
    
    February 14, 2017
    
    where did 80n come from? I’m lost. I had trouble with geometry on the test.
    
    Reply
    1. Magoosh Test Prep Expert
      
      February 14, 2017
      
      Hi Tierra,
      
      I’m happy to help 🙂 First, just to make sure, the value is 80pi (not 80n). This value is the volume of the right cylinder, while 16pi is the volume of the cone.
      
      The volume of a cylinder with a base radius r and height h is pi*(r^2)h
      
      where r is the radius of the circular base and h is the height of the cylinder.
      
      In the figure, we see that
      
      r = 4
      h = 5
      
      Plugging those values into the formula above, we get
      
      pi*(4^2)5 = pi*16*5 = 80pi
      
      😀
      
      I hope this clears up your doubts! If not, let us know 🙂
      
      Reply
Robin

August 1, 2019

Hmmm-this is a little scary. You have alot of mistakes after going through all the blog links, please don’t get it twisted, I am having a terrible time passing the core math so don’t take it as judging, but before I sign up is the paid service better than the blog problems as far as the error rates?

Reply