General memory for maths MCQ Flashcards
equation for binomial coefficient nCr + definition
n!/r!(n-r)! the number of ways of choosing r objects from n objects
Sum of angles and single angle of a regular triangle
180, 60
Sum of angles and single angle of a regular square
350, 90
Sum of angles and single angle of a regular pentagon
540, 108
Sum of angles and single angle of a regular hexagon
720, 120
Sum of angles and single angle of a regular heptagon
900, 128.571
Sum of angles and single angle of a regular octagon
1080, 135
Sum of angles and single angle of a regular nonagon
1260, 140
Sum of angles and single angle of a regular decagon
1440, 144
exterior angle equation
360/n
interior angle equation
180(n-2)
area of a parallelogram
base x height
features of a parallelogram
opposite angles are equal, angles next to each other add up to 180 degrees, the diagonals bisect the angles, diagonals bisect into 2 congruent triangles
features of a rhombus
the diagonals are perpendicular, opposite angles are equal, angles adjacent add up to 180 degrees, diagonals bisect the angles and also the rhombus into 2 isosceles triangles/4 congruent right angled triangles
area of a trapezium and angle features
0.5(sum of parallel sides) x height - the interior angles of the parallel sides sum to 180 degrees
features of a kite
diagonals meet at 90 degrees, 2 sides of the same length, the angle made at the point 2 different length sides are made is equal to the opposite side.
Area of a kite
(diagonal x diagonal)/2
define congruence
2 shapes are congruent is they are exactly the same. I.e same shape and size, or if one has the same shape and size as the mirror image of the other
What are the conditions of congruence
FOUR CONDITIONS: SSS, SAS, ASA and RHS (right angle, hypotenuse, side) - have to occur next to each other
What are similar triangles
Similar triangles have the same size angles (congruent angles) and corresponding SIDES in PROPORTION.