WEEK 2 Flashcards
is a branch of mathematics that studies triangles and the relationships between their sides and the angles between sides.
Trigonometry
deals with the triangles bounded by arcs of great circles.
Spherical Trigonometry
determined by rotating a ray (half-line) about its endpoint called vertex.
plane angle
for an angle in standard position is the positive acute angle between the x-axis and the terminal side of angle .
Reference angle
Two angles which when placed in standard position, have coincident terminal sides
Coterminal angles
is the angle from the horizontal up to the line of sight from the observer to an object above.
angle of elevation
it is the angle from the horizontal down to the line of sight from the observer to an object below.
angle of depression
is a triangle having no
equal sides.
A scalene triangle
is a triangle having at least two equal sides.
An isosceles triangle
is a triangle having three equal sides.
An equilateral triangle
is the point of intersection of all the medians of a triangle.
Centroid
- is the point of intersection of all angle bisectors in a triangle.
- is also the center of the inscribed circle in a triangle.
Incenter
- is the point of intersection of all perpendicular bisectors of a triangle.
- is also the center of the circumscribed circle.
Circumcenter
is the point of intersection of all the altitudes of a triangle.
Orthocenter
is the center of the escribed circle.
Excenter
is a circle that can be constructed for any given triangle by passing through nine significant points defined from the
triangle.
nine-point circle
A line that passes through centroid, circumcenter, orthocenter, and the center of a nine-point circle of a triangle is called
Euler’s line
The incenter lies on the Euler line only for
Isosceles triangle
a triangle is a segment from vertex to the midpoint of the opposite side.
Median
It is a theorem relating the length of a median of a triangle to the lengths of its sides. Specifically, in any triangle ABC, if “m” is a median
Apollonius’ theorem
is a segment or ray that bisects an angle and extends to the opposite side.
Angle Bisector
a segment from a vertex perpendicular to the opposite side.
Altitude
“In a right triangle, the square of the length of the hypotenuse is equal to the sum of the squares of the lengths of the legs”
The Pythagorean Theorem
is a circle on the Cartesian Plane that has a radius of 1 unit and is centered at the origin (0, 0).
A unit circle
ASTC
Add : All functions in the first quadrant are positive.
Sugar : Sine is positive in the second quadrant.
To : Tangent is positive in the third quadrant.
Coffee : Cosine is positive in the fourth quadrant.
is a triangle that contains
no right angle.
Oblique triangle
is the branch of spherical geometry that deals with the metrical relationships between the sides and angles of spherical triangles, traditionally expressed using trigonometric functions. On the sphere, geodesics are great circles
Spherical Trigonometry
sometimes referred to in older texts as Mollweide’s equations, named after Karl Mollweide, is a set of two relationships between sides and angles in a triangle. It can be used to check solutions of triangles.
Mollweide’s Formula
is a branch of mathematics concerned with questions of shape, size, relative position of figures, and the properties of space.
Geometry