Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
15 Cards in this Set
- Front
- Back
|
A great circle of a sphere is...
|
a set of points that is the intersection of the sphere and a plane containing the center of the sphere.
|
|
|
Antipodal points...
|
are the two points of intersection of a sphere with a line through its center.
|
|
|
A birectangular quadrilateral...
|
is a quadrilateral that has two sides perpendicular to a third side.
|
|
|
Parts of a birectangular quadrilateral.
|
Angle A and angle B are base angles.
Angle C and angle D are summit angles. |
|
|
A Saccheri quadrilateral...
|
is a birectangular quadrilateral whose legs are equal.
|
|
|
The summit angles of a Saccheri quadrilateral...
|
are equal.
|
|
|
The line segments connecting the midpoints of the base and summit of a Saccheri quadrilateral are...
|
perpendicular to them both.
|
|
|
If the legs of a birectangular quadrilateral are unequal, then...
|
the summit angles opposite them are unequal in the same order.
|
|
|
If the summit angles of a birectangular quadrilateral are unequal, then...
|
the legs opposite them are unequal in the same order.
|
|
|
The Lobachevskian Postulate
|
The summit angles of Saccheri quadrilateral are acute.
|
|
|
Lobachevskian Theorem 1
|
The summit of a Saccheri quadrilateral is longer than its base
|
|
|
Lobechevskian Theorem 2
|
A midsegment of a triangle is less than half as long as the third side.
|
|
|
Lobachevskian Theorem 3
|
The sum of the angles of a triangle is less than 180°.
|
|
|
Corollary to Lobachevskian Theorem 3
|
The sum of the angles of a quadrilateral is less than 360°.
|
|
|
Lobachevskian Theorem 4
|
If two triangles are similar, they must also be congruent.
|
