Busy. Please wait.

show password
Forgot Password?

Don't have an account?  Sign up 

Username is available taken
show password


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
We do not share your email address with others. It is only used to allow you to reset your password. For details read our Privacy Policy and Terms of Service.

Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
Don't know
remaining cards
To flip the current card, click it or press the Spacebar key.  To move the current card to one of the three colored boxes, click on the box.  You may also press the UP ARROW key to move the card to the "Know" box, the DOWN ARROW key to move the card to the "Don't know" box, or the RIGHT ARROW key to move the card to the Remaining box.  You may also click on the card displayed in any of the three boxes to bring that card back to the center.

Pass complete!

"Know" box contains:
Time elapsed:
restart all cards
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how



A triangle with three sides of equal length, and three angles of equal measures equilateral triangle
A triangle in which two sides are of equal length, and two angles have the same measure isosceles triangle
A triangle in which all three sides have different lengths, and all three angles have different measures scalene triangle
A triangle with one angle measuring 90 degrees right triangle
congruent having exactly the same size and shape
polygon a closed figure, made up of sides that do not overlap
regular polygon a polygon in which all sides are the same length, and all angles have the same measure
parallel lines that are always the same distance apart, and never intersect
perpendicular lines that intersect to form four right angles
quadrilateral a four sided polygon
pentagon a five sided polygon
hexagon a six sided polygon
octagon an eight sided polygon
acute angle an angle measuring less than 90 degrees
obtuse angle an angle measuring greater than 90 degrees, but less than 180 degrees
right angle an angle measuring exactly 90 degrees
reflex angle an angle measuring more than 180 degrees
parallelogram a quadrilateral with two pairs of parallel sides
trapezoid a quadrilateral with one pair of parallel sides
vertex point where two lines meet to form an angle
Created by: MrArchung