MATH REGENTS REVIEW THINGS TO REMEBER Flashcards
(20 cards)
Propertys of a Quadrilateral
- 4 sided polygon
- Sum of interior angles = 360°
Propertys of a Trapizoid
one pair of parallel sides
Propertys of an Isosceles Trapazoid
- Each pair of base angles are congruent
- Diagonals are congruent
- one pair of congruent sides (the legs not bases)
Properties of a parallelogram
- Oppisite sides are parallel
- oppisite sides are congruent
- oppisite angles are congruent
- consecutive angles are 180°
- Diagonals bisect eachother
Properties of a rectangle
- all angles are right angles
- diagonals are congruent
Rhombus
- all sides are congruent
- diagonals are perpendicular
- diagonals bisect oppisite angles
Square
- all angles are right angles
- diagonals are congruent
- all sides are congruent
- diagonals are perpendicular
- diagonals bisect oppisite angles
distance formula
d = √(x₁-x₂)²+(y₁-y₂)²
Area of a circle
πr²
Circumference
2πr
Orthocenter
3 altitudes
Incenter
3 angle bisectors
Centroid
3 medians
circumcenter
3 perpendicular bisectors
partitions
x₁+kΔx=y₁+kΔy
30 60 90 triangle
side oppisite 30° = x
side oppisite 60° = x√3
side oppisite 90° = 2x
45 - 45 - 90 triangle
both sides oppisite 45° = x
side oppisite 90° = x√2
law of sines
Does not require a right angle:
a/sin A = b/sin B = c/sin C
- Sin’s A, B and C represnt angles
- a , b , c (notice lower case) represnt sides
Can be used if you know one angle and its oppisite side abd another angle you can use law of sines.
Sin and cos relationship
Only works in a right triangle.
- sin(θ) = cos (90° - θ)
- cos(θ) = sin (90° - θ)
If two angles add up to 90° then:
- the sine of one = the cosine of the other
- the cosine of one = the sine of the other
equation of a circle
(x-h)^2 + (y-k)^2 = r^2
(h,k) is the center and r is the radius.
