PRE-CAL (NO SOLVE, GENERAL QUESTIONS) Flashcards
The word ____ comes from a Latin word named ‘angulus,’ meaning “corner.”
Angle
Point where the arms meet.
Vertex
Two straight line segments form a vertex.
Arms
If a ray is rotated about its endpoint, the measure of its rotation is called angle
between its initial and final position.
Angle
An ______ is the opposite of an acute angle. It is the angle which lies between 90
degrees and 180 degrees.
Obtuse Angle
An ______ is greater than 90 degrees and less than 180 degrees
Obtuse Angle
An _______ lies between 0 degree and 90 degrees
Acute Angle
An _______ is one that is less than 90 degrees.
Acute Angle
A ________ is always equal to 90 degrees.
Right Angle
A ______ is 180 degrees when measured
straight angle
The figure illustrates a straight angle or a 180-degree angle. You can see that it is just
a straight line because the angle between its arms is 180 degrees.
Straight Angle
Any angle that has a measure which is greater than 180 degrees but less than 360
degrees.
Reflex Angle
_____ are those angles which are measured in a counterclockwise direction
from the base. In most cases, _____ are used to represent angles in geometry.
From the origin, if an angle is drawn in the (+x, +y) plane, it forms a _______
Positive Angle
______ are those angles which are measured in a clockwise direction from the
base. From the origin, if an angle is drawn towards the (x, -y) plane, it forms a _______
Negative angles
▪ An amount of opening of an angle.
▪ Amount of the rotation from the initial side of an angle to its terminal side.
Angular Measure
▪ Is the measure of the central angle subtended by an arc of a circle whose length is equal
to the radius of the circle.
Radian
- Two angles in standard position are said to be ________ if their terminal sides
coincide.
Co Terminal
- Is the length of the arc of the circle that subtends the angle
Linear Measure
- Is the circle centered at the origin and of a radius 1 unit. Its equation is given 𝑥
2 + 𝑦
2 =
1
Unit Circle
- Is the acute angle formed by the terminal side of 𝜃 and the x-axis.
Reference Angle
Is a statement that is true on condition that the variable replaced with the correct value.
Conditional Equation
Is defined as the angle formed by the line of sight and the horizontal plane for an object
below the horizontal.
Angle of depression
- The angle formed by the horizontal and the line of sight
Angle of Elevation
✓ Is an identity that involves trigonometric functions of one or more variables.
Trigonometric Identities
