Geometry Flashcards
congruent line segments
line segments that have equal lengths
similar triangles
triangles that have the same shape but not necessarily the same size
congruent angles
angles that have equal measures
acute angle
angle with measure less than 90 degrees
obtuse angle
angle with measure between 90 and 180 degrees
polygon
a closed figure formed by 3 or more line segments (sides).
vertices
endpoints of the sides of a polygon
quadrilateral can be divided into how many triangles
Two
pentagon can be divided into how many triangles
Three
regular polygon, or regular octagon
a polygon in which all sides are congruent and all interior angles are congruent
equilateral triangle
a triangle with three congruent sides. measures of 3 interior angles of an equilateral triangle are also equal, and are 60 degrees each.
isoscoles triangle
triangle with AT LEAST TWO equal sides, with angles opposite the 2 sides being congruent.
right triangle
a triangle with an interior right angle (90 degrees)
hypotenuse
the side opposite the right angle in a right triangle
pythagorean theorem
a squared plus b squared equals c squared
congruent circles
circles with equal radii are congruent circles
a chord
any line segment joining two points on the circle is called a chord
an arc
given any two points on a circle, an ARC is the part of the circle containing the two points and all points in between them
central angle of a circle
an angle with its vertex at the center of the circle
measure of an arc
measure of its central angle, the angle formed by two radii that connect the center of the circle to two endpoints of the arc.
sector of a circle
a region bounded by an arc of the circle and two radii.
tangent to a circle
a line that intersects the circle at exactly one point, called the point of tangency
point of tangency
the point at which a tangent intersects a circle
what does it mean that a polygon in INSCRIBED in a circle?
all of the polygon’s vertices lie on the circle (or, the circle is CIRCUMSCRIBED about the polygon).
what does it mean that a circle is CIRCUMSCRIBED about a polygon?
all of the polygon’s vertices lie on the circle (or, the polygon is INSCRIBED in the circle).
concentric circles
two or more circles with the same center
volume of a rectangular solid
the product of its three dimensions (volume equals length times width times height).
circular cylinder
two bases that are congruent circles and a lateral surface made up of all line segments that join points on the two circles and are parallel to the line segment joining the centers of the two circles (think: a can of soda).
volume of a right circular cylinder with a height of h and a base with radios r equals
the product of the height and the area of the base (or h times (pi)(r squared)(h)
surface area of a right circular cylinder
the sum of the areas of the two bases and the lateral area, or two times (pi r squared) PLUS two pi r h.
