Trig Math 2 Unit 3 Flashcards
Pythagorean Triple
a set of nonzero whole numbers, a b and c, that satisfy the P. Theorem
Common p. triples
3, 4, and 5
5, 12, and 13
8, 15, and 17
7, 24, and 25
Converse of the Pythagorean Theorem
if the square of the length of one side of a triangle is equal to the sum of the squares of the lengths of the other 2 sides then the triangle is a right triangle
Pythagorean theorem(ish) if the triangle isn’t right
a^2 + b^2 > c^2 -acute
a^2 + b^2 < c^2 -obtuse
Special right triangles examples
45-45-90
30-60-90
45-45-90 triangle theorem
in a 45-45-90 triangle, both legs are congruent and the length of the hypotenuse is root 2 times the length of a leg
30-60-90 triangle theorem
the length of the hypotenuse is twice the length of the shorter leg. the length of the longer leg is root 3 times the length of the shorter leg
How to find a missing side using trig ratios
decide which ratio, set up proportion, solve, round to nearest hundredth
What does your calculator have to be in?
DEGREES
How to find missing angles using trig ratios
decide which ratio, set up proportion, solve, round to nearest hundredth (will use the inverse function)
Area of triangles given SAS and formula
the area of a triangle is one half the product of the lengths of 2 sides and the sine of the included angle
A=1/2absinC
- a and b are sides
- *C is the included angle
Heron’s formula
The area of a triangle with side lengths a, b, and c is
A= [the square root of] s*(s-a)(s-b)(s-c)
s=1/2(a+b+c)
radius
line segment from the center of a regular polygon to a vertex (if a circle is drawn around the polygon, the segment is also the radius of the center)
central angle
the angle formed at the center of the polygon by any 2 adjacent vertices (adjacent radii)
apothem
line segment from the center of a regular polygon perpendicular to a side
