Trigonometery Flashcards
An equilateral triangle has:
All the same angles and all the same lengths.
If the base and length of a triangle are not the same you can:
Reflect the triangle to make it equilateral.
Then you can solve for sides, by either dividing by two (because the base was doubled)
Or by using Pythagorean theorem.
Pi amount of Radians equals:
180 degrees
What is a rotation angle?
A rotation angle is an angle that is formed by rotating an initial arm through angle theta around a fixed point(the vertex.)
What is a positive angle?
A positive angle results from a COUNTER-CLOCKWISE rotation.
What is a negative angle?
A negative angle results from a clock-wise rotation.
What is Standard Position?
Standard position is when the angle’s vertex is at the origin and one ray is on the x-axis.
What is a ray?
Another word for arm in trig.
What is a terminal arm?
A terminal arm arm is the arm that indicates the end.
-opposite of initial arm
What is a radian?
A radian is the ration between the length of an arc and its radius in a given circle.
(The are 2(3.34159) of them in a full circle).
What is the formula for a radian?
Radian = arc length / radius
What is a coterminal angle?
Coterminal angles are angles in standard position with the same terminal arms.
What is a principal angle?
A principal angle is the smallest positive coterminal angle.
How many coterminal angles are possible?
An infinite amount.
What is the formula for coterminal angles?
θ ± (360 °)n OR θ ± 2πn , nER
