Plane Geometry Flashcards
Book of Euclid which given emphasis on Plane Geometry
Elements
Branch of Geometry that deals with plane figure or geometrical shapes of two dimensions
Plane Geometry
Branch of Geometry deals with properties of geometrical shapes of three dimensions such as cones, pyramids, cylinders
Solid Geometry
Branch of Geometry based on the assumptions of Euclid
Euclidean Geometry
Branch of Geometry that is not based on the assumption of Euclid
Non-Euclidean Geometry
Branch of Geometry that deals with the study of those properties of plane figures that are unchanged when given set of points is projected onto a second plane
Projective Geometry
Branch of Geometry which specializes on the study of triangle
Trigonometry
Branch of Geometry that deals with geometric problems by using the coordinate systems and transforming them into algebraic problems
Analytic Geometry
Branch of Geometry that applies differential and integral calculus to curves, surfaces and other geometric entities
Differential Geometry
What are the 5 basic postulate of Euclid?
- A unique line can be drawn between any two points
- Such line can be extended indefinitely in either direction
- A circle can be drawn in a plane using a given point (a center) and a given distance(a radius)
- All right angles are equal
- Given a line and a point not on the line, there exist exactly one line parallel to the original line passing through the given point (aka parallel postulate)
A dimensionless geometric figure having no properties other than location or place
Point
The shortest distance between any two points.
Line
The opening between two lines or planes that meet
Angle
What is a straight angle?
Equal to 180 degrees or (pi) radians
What is a reflex angle?
Greater than 180 degrees but less than 360 degrees
What is a Full angle or Perigon?
Equal to 360 degrees or 2*pi radians
Two angles with a common leg
Adjacent angles
Two angles where the sum is a right angle
Complementary Angles
Two angles where the sum is a straight angle (180degrees)
Supplementary angles
Two angles whose sum is a perigon
Explementary angles
Angles formed by two intersecting lines
Vertical Angles
It is a unit of angle based on sexagesimal system
Degree
Standard angular measure in international system of units
Radian
It is a measure ofan angle which is 1/6400 of the full circle
Mil
1 Revolution in terms of Gon
400
1 Revolution in terms of Mil
6400
Number of sides of regular Hectagon
100
Number of sides of a regular Megagon
10^6
Number of sides of a regular googolgon
100^100
How many sides does Undecagon have?
11
How many sides of Dodecagon
12
It is the inward pointing angle of the concave polygon
Reentrant angle
Other angles of a concave polygon except the Reentrant angle
Salient Angle
it is the line connecting two opposite vertices
diagonal
Number of diagonals formula
No. of Diagonals=(n/2)*(n-3)
where n=number of sides
formula of sum of interior angles
(n-2)*180degrees
It is the angle subtended by the prolongation of one side to the next
deflection angle
The sum of all deflection angle equals to?
360 degrees
A triangle where all sides are equal
Equilateral Triangle
A triangle where two sides are equal
Isosceles Triangle
A triangle where no two sides are equal
Scalene Triangle
Each interior angle is less than a right angle
Acute triangle
One angle is a right angle
Right triangle
One angle is greater than right angle
Obtuse triangle
A triangle which is not a right triangle is called what?
Oblique Triangle
A triangle with 3,4,5 units
Egyptian Triangle
A triangle inscribed in a given triangle whose vertices are the feet of the three perpendicular to the sides from some points inside a given Triangle
Pedal Triangle
An isosceles triangle with sides is to its base in the golden ratio; its angles are 72,72 and 36 degrees
Golden Triangle
What is a rhombus?
A type of quadrilateral with all sides are equal but no angle equal to right angle
What is a parallelogram?
Both pairs of opposite sides are parallel.
What is another term for a parallelogram?
Rhomboid
A quadrilateral wherein only two sides are parallel
Trapezoid
A quadrilateral where no two sides are parallel
Trapezium
What is a Kite quadrilateral?
A convex quadrilateral whose adjacent sides are equal in pair
What is a deltoid quadrilateral?
A concave quadrilateral whose adjacent sides are equal in pair
It is a quadrilateral whose vertices lie on a circle
Cyclic quadrilateral
Area of a rhombus
A=bh
where b=base
h=height
Area of rhombus given two diagonals
A=(1/2)d1*d2
Are of rhombus given a side and included angle
A=a^2(sin(theta))
Area of parallelogram given base and altitude
A=bh
Area of parallelogram given two diagonals and included angle
A=(1/2)d1d2sin(theta)
Area of parallelogram given two sides and an interior angle
A=ab*sin(theta)
Area of a trapezoid
A=1/2(B+b)*h
where B=length of upper base
b=length of lower base
h=height
Area of a Trapezium (General Quadrilateral)
A=1/2(d1d2)*sin(theta)
where d1 and d2 are the lengths of diagonal
Area of a general quadrilateral given four sides and opposite angles
A=sqrt((s-a)(s-b)(s-c)(s-d)-abcd(cos^2(theta)))
theta=(A+C)/2 or (B+D)/2
s=(a+b+c+d)/2
Area of a cyclic quadrilateral
A=sqrt((s-a)(s-b)(s-c)*(s-d))
A=sqrt((s-a)(s-b)(s-c)*(s-d
radius of the circle circumscribing the quadrilateral Formula
r=(sqrt((ab+cd)(ac+bd)(ad+bc)))/(4A)
Area of quadrilateral circumscribing a circle
A=rs=sqrt(abcd)
where s=(a+b+c+d)/2
Area of a regular polygon
A=(1/4)*(na^2)cot(180/n)
where a=length of side
n=number of sides
Perimeter of a regular polygon
P=na
where a=length of side
n=number of sides
Area of a regular polygon circumscribing a circle
A=nr^2tan(180/n)
Perimeter of a regular polygon circumscribing a circle
P=2nr*tan(180/n)
Area of a regular polygon inscribed in a circle
A=(1/2)*nr^2sin(360/n)
Perimeter of a regular polygon inscribed in a circle
P=2nr*sin(180/n)
It is the length of a circle between two points on the circle
Arc
a line touching the circle at one point. It is also perpendicular to the radius of the circle
Tangent
A line cutting the circle in two place
Secant of a circle
It is the longest chord of a circle that passes through the center
Diameter
Distance from the center to the circle
radius
the segment of a secant bounded by the circle
Chord
Area bounded by two radii and the included arc
Sector of a circle
Area bounded by a chord and the arc subtending the chord
Segment
An angle whose vertex is at the center of a circle and whose sides are the radii
Central Angle
An angle whose vertex is along the periphery or circumference and its sides are the chords
Angle subtended by the chord
Are of sector of a circle
A=(1/2)*(rc) A=(1/2)*(r^2*theta) r=radius c=arc length theta=central angle
Area of segment of a circle
A=A(sector)-A(triangle AOB)
If a central angle and a peripheral angle are subtended by the same arc, then the central angle is ________ as large as the peripheral angle
Twice
What is the relationship of the inscribed angles subtending the same arc?
Equal
Inscribed angles subtended by the diameter of a circle are ______ angles
right angles (90 degrees)
What is the chord theorem formula?
ab=cd
What is the secant theorem formula?
a(a+b)=c(c+d)
What is Secant-Tangent theorem formula?
t^2=a*(a+b)
Area of an ellipse formula
A=pi*ab
it is a general term for all angles that lie on a plane surface
plane angle