Geometery Flashcards
Rules for congruent triangles
sss
sas
aas
rhs
(aaa)
parallelogram vs rhombus
parallelogram = tilted rectangle
rhombus = tilted square
What do the s, a, r and h mean in the rules for congruent triangles?
s = side
a= angle
r= right angle
h= hypotenuse
polygon
A closed 2D shape with only straight sides.
What do we consider a regular polygon?
A polygon where all of its sides are the same length and all its angles are the same size.
How many lines of symmetry do regular polygons have?
It’s the same as the number of sides.
What order of rotational symmetry do regular polygons have?
It’s the same as the number of sides.
What do we mean by congruent shapes?
Shapes of identical shape and size.
area of a trapezium?
A = 1/2 (a+b) h
curved surface area of a cone formula
πrl
volume of a cone formula
1/3 π r² h
How many pairs of parallel sides does a kite have?
0
How many lines of symmetry does a trapezium have?
0
What must the internal angles of a quadrilateral add up to?
360°
What feature must be identical for two shapes to be considered similar?
Their shape
To confirm that two shapes are similar, what can we do?
Check that all of the angles are the same size.
When discussing shapes, do the terms ‘similar’ and ‘mathematically similar’ mean the same thing?
Yes
what does h stand for?
Perpendicular height
Area of a rectangle?
A = l x w
Area of a parallelogram?
A = b x h
Area of a triangle?
A = 1/2 x b x h
What is a chord?
A straight line which connects two points on the circumference of a circle.
What is a segment?
The two parts of a circle when a chord splits it in two.
What is the minor segment?
The smaller segment.
What is the major segment?
The larger segment.
What is an arc?
A section of a circle’s circumference.
(the smaller is the minor arc and the larger is the major arc)
What is a sector?
A section of a circle as if you’ve cut a piece of cake.
Involves two radii which each go from the centre of the circle to the circumference, joined by an arc.
There are two - major and minor.
Length of an arc formula?
x/360 x 2πr
Area of a sector formula?
x/360 x πr²
How many edges does a cube have?
12
How many faces does a cube have?
6
How many vertices does a cube have?
8
How many vertices does a sphere have?
0
How many faces does a sphere have?
1
How many edges does a sphere have?
0
How many vertices does a cylinder have?
0
How many edges does a cylinder have?
2
How many faces does a cylinder have?
3