Search
Create
Log in
Sign up
Log in
Sign up
Geometry
STUDY
Flashcards
Learn
Write
Spell
Test
PLAY
Match
Gravity
Terms in this set (40)
Tangent
intersects a circle in only 1 place.
Secant
intersects a circle in 2 places.
Central angle
is equal to its intercepted arc.
Inscribed angle
is equal to ½ its intercepted arc.
Adjacent angles
share a common vertex, a common side, but not common interior points.
Complementary angles
2 angles when added together that equal 90 degrees.
They do not have to be adjacent angles.
Supplementary angles
2 angles when added together that equal 180 degrees.They do not have to be adjacent angles.
Vertical angles
are congruent
Alternate interior angles
are congruent.
Corresponding angles
are congruent.
Sum of the angles in a triangle
the 3 angles of a triangle add up to 180 degrees.
Triangles classified by sides
scalene triangles have no equal sides.
isosceles triangles have at least 2 equal sides.
equilateral triangles have 3 equal sides.
Triangles classified by angles
acute triangles have 3 acute angles.
right triangles have a 90 degree and 2 acute angles.
obtuse triangles have an obtuse and 2 acute angles.
Exterior angle of a triangle
equals the sum of the 2 opposite interior angles.
Isosceles triangles
sides opposite congruent angles are congruent.
angles opposite congruent sides are congruent.
Triangle inequality theorem
the sum of 2 sides of a triangle must be greater than the 3rd side.
Median
bisects the opposite side into 2 congruent line segments.
median segments are in a ratio of 2 to 1.
Angle bisector
bisects an angle into 2 congruent angles.
Altitude
makes a right angle with the opposite side.
Perpendicular bisector
bisects and makes a right angle with a side of a triangle.
Similar triangles
angles in similar (∼) triangles are congruent.
sides are in proportion.
Proving triangles similar
need only 2 angles to be congruent to prove 2 triangles similar.
Proving triangles congruent
can not be angle angle side (A.S.S.) or side side angle(S.S.A.).
C.P.C.T.C.
corresponding parts of congruent triangles are congruent.
Pythagorean theorem
a squared plus b squared equals c squared.
the hypotenuse is always c.
Perimeter
distance around the outside of a polygon.
Transformations
Dilations are a capital D.
Reflections are a lower case r.
Rotations are a capital R.
Translations are a capital T.
Dilation
Multiply both coordinates by the scale factor.
Reflection over the x axis
change the sign of the y coordinate.
Reflection over the y axis
change the sign of the x coordinate.
Reflection over the line y=x
switch the x and y coordinates.
Rotation of 90 degrees
graph the coordinate. rotate the graph 90 degrees counter clockwise and read the new point.
Rotation of 180 degrees
graph the coordinate. rotate the graph 180 degrees counter clockwise and read the point.
Rotation of 270 degrees
graph the coordinate. rotate the graph 270 degrees counter clockwise and read the point.
Translation
add the 2 integers to the orginal coordinate. add the first integer to the x coordinate and the second integer to the y coordinate.
Plane
has no thickness and extends forever in all directions.
Line
has no thickness, but it extends forever in both directions.
Collinear points
are points that lie on the same line
Coplanar points
are points that lie on the same plane
Parallel lines
are lines on the same plane that never touch.
THIS SET IS OFTEN IN FOLDERS WITH...
Geometry
51 Terms
Gail_Eddy
Geometry
27 Terms
Drew_Demich
TEACHER
Geometry
101 Terms
callen83
Geometry
42 Terms
Shannon_Stromberg
;