Definitions
Postulates & CNs
Book 1
Book 3
Wildcard
100

The definition of a point

What is that which has no part?

100

Postulate 1

What is "to draw a straight line from any point to any point"?

100

In ______________, the angles at the base are equal to one another, and the angles under the base are equal to one another. 

What are isosceles triangles?

100

If two circles cut one another, then they do not __________.

What is "have the same center"?

100

To cut something in half

What is bisect?

200

The definition of a line

What is breadthless length?

200

Postulate 3

What is "to describe a circle with any center and distance"?

200

If in a triangle two angles equal one another, then _______________.

What is "the sides opposite the equal angles also equal one another"?

200

A circle does not touch a circle at more than _______ point(s). 

What is one?

200

When each side of the figure touches the circumference of the circle

What is a figure circumscribed about a circle?

300

The angle which, when a point is taken on the circumference of the segment and straight lines are joined from it to the ends of the straight line which is the base of the segment, is contained by the straight lines so joined.

What is an angle in a segment?

300

Common Notion 3

What is "if equals are subtracted from equals, then the remainders are equal"?

300

If a straight line standing on a straight line makes angles, then they make ____.

What are two right angles or angles equal to two right angles?

300

Of straight lines in a circle ___________ is greatest. 

What is the diameter?

300

In a circle, the angle in _____________ is right. 

What is a semicircle?

400

The figure contained by a straight line and the circumference of a circle

What is a segment?

400

Common Notion 5

What is "the whole is greater than the part"?

400

In any triangle, if one side is produced, then the exterior angle is greater than either of the ______________.

What are interior and opposite angles?

400

In equal circles, equal angles stand on ____________. 

What are equal circumferences?

400

Its ends are on the circumference of a circle

What is a line fitted into a circle?

500
The definition of a circle

What is a plane figure contained by one line such that all the straight lines falling upon it from one point among those lying within the figure equal one another?

500

Postulate 5

What is "if a straight line falling on two straight lines makes the interior angles on the same side less than two right angles, the two straight lines, if produced indefinitely, meet on that side on which are the angles less than the two right angles"?

500

In any parallelogram, the __________ of the parallelograms about the diameter are equal to one another. 

What are complements?
500

If a straight line touches a circle, and from the point of contact a straight line is drawn at right angles to the tangent, then ___________ will be on the straight line so drawn.


What is the center of the circle?

500

If a straight line falling on two straight lines makes the _________ equal to one another, then the straight lines are parallel to one another. 

What are alternate angles?