3.1 and 3.2 geometry terms Flashcards
(17 cards)
Circumference
The perimeter of a circle or distance around a circle
Perimeter of a polygon
Sum of the lengths of its sides
Pi
The ratio of circumference to diameter in any circle
Postulate circumference of a circle
The circumference of a circle is the product of pi and the diameter of the circle
Formula for circumference
C=d(pi)
Postulate area of a region enclosed by a simple closed curve
For every simple closed curve and unit square, there is a positive real number that tesselate the region enclosed by the simple closed curve
Area of rectangle
Product of its length and width
LXW
Postulate congruent triangles
Any two triangles whose corresponding angles and sides are congruent have the same area
Theorem area of a right triangle
The area of a right triangle is half the product of the length of its legs
Altitude
A line segment from a vertex of a triangle that is perpendicular to the opposite side of the triangle. The length of the altitude is also referred to as the altitude or height. The side to which the altitude is drawn is called the base of the triangle.
Theorem area of a right triangle
The area of a triangle is half the product of the length of one side and the height to that side.
Theorem area of a parallelogram
The area of a parallelogram is equal to the product of the length of one of its sides and the height to that side. The length of a perpendicular segment having one end point at a vertex and the other end point on the opposite parallel side (or side extended) is called height.
Parallelogram formula
A=bh
Theorem area of a trapezoid
Equal to half the product of the height and the sum of the lengths of its two bases
A=1/2(b1+b2)h
Apothem
The perpendicular distance from the center of a regular polygon to any side
Theorem area of a regular polygon
Equal to half the product of the perimeter of the polygon and the perpendicular distance from its center to one of its sides
A=1/2ap or a=1/2a(sn) A=apothem s= side length n=number of sides
Theorem area of circle
Equal to the product of pi and the square of the radius
Pir2
