aaaaaaaaaa

1. Trigonometry
The branch of mathematics that deals with the relationships between the sides and the angles of
triangles and the calculations based on them, particularly the trigonometric functions.
Trigonometry (from Greek trigōnon "triangle" + metron "measure"[1]) is a branch of mathematics that
studies triangles and the relationships between their sides and the angles between these sides. Trigonometry
defines the trigonometric functions, which describe those relationships and have applicability to cyclical
phenomena, such as waves. The field evolved during the third century BC as a branch of geometry used
extensively for astronomical studies.[2] It is also the foundation of the practical art of surveying.
Angle
figure formed by the intersection of two straight lines; the lines are called the sides of the angle and their
point of intersection the vertex of the angle. Angles are commonly measured in degrees (°) or in radians. If
one side and the vertex of an angle are fixed and the other side is rotated about the vertex, it sweeps out a
complete circle of 360° or 2π radians with each complete rotation. Half a rotation from 0° or 0 radians results
in a straight angle, equal to 180° or π radians; the sides of a straight angle form a straight line. A quarter
rotation (half of a straight angle) results in a right angle, equal to 90° or π/2 radians; the sides of a right
angle are perpendicular to one another. An angle less than a right angle is acute, and an angle greater than a
right angle is obtuse. Two angles that add up to a right angle are complementary. Two angles that add up to
a straight angle are supplementary. One of the geometric problems of antiquity is the trisection of an angle.
Angles can also be formed by higher-dimensional figures, as by a line and a plane, or by two intersecting
planes.
Type of Angle Description
Acute Angle an angle that is less than 90°
Right Angle an angle that is 90° exactly
Obtuse Angle an angle that is greater than 90° but less than 180°
Straight Angle an angle that is 180° exactly
Reflex Angle an angle that is greater than 180°
Object 1

2. 1. The sum of the interior angles in a regular polgyon is equal to 180(n-2), where n is the number of sides of the polygon.
#Sides in a Regular Sum of Interior Angles Measure of Each Interior Sum of Exterior Angles
Polygon Angle
180(n-2) 360o
n [180(n-2)]
n
3 180 60 360o
4 360 90 360o
5 540 108 360o
6 720 120 360o
7 900 128.57 360o
8 1080 135 360o
9 1260 140 360o
10 1440 144 360o
The regular polygons displayed on the right are cyclic polygons.
Note: Notice each pair of exterior angles are equal. Thus for each interior angle, there is one exterior
angle. Any regular polygon has n interior angles and nexterior angles.

3. part of function or example
example sentences
speech "job" words
(to) be, have,
do, like, work, EnglishClub.com is a web site.
Verb action or state
sing, can, Ilike EnglishClub.com.
must
pen, dog,
work, music, This is my dog. He lives in
Noun thing or person
town, London, myhouse. We live in London.
teacher, John
a/an, the, 2,
some, good, I have two dogs. My dogs
Adjective describes a noun
big, red, well, are big. I like big dogs.
interesting
quickly,
describes a verb, My dog eats quickly. When he
silently, well,
Adverb adjective or isvery hungry, he
badly, very,
adverb eats reallyquickly.
really
I, you, he,
Pronoun replaces a noun Tara is Indian. She is beautiful.
she, some
links a noun to to, at, after,
Preposition We went to school on Monday.
another word on, but
joins clauses or I like dogs and I like cats. I like
Conjunction sentences or and, but, when cats and dogs. I like dogs but I
words don't like cats.
short
exclamation,
oh!, ouch!, hi!, Ouch! That hurts! Hi! How are
Interjection sometimes
well you? Well, I don't know.
inserted into a
sentence
An adjective modifies a noun or a pronoun by describing, identifying, or quantifying words. An adjective usually precedes the noun
or the pronoun which it modifies.
In the following examples, the highlighted words are adjectives:
The truck-shaped balloon floated over the treetops.
Mrs. Morrison papered her kitchen walls with hideous wall paper.
The small boat foundered on the wine dark sea.
The coal mines are dark and dank.
Many stores have already begun to play irritating Christmasmusic.
A battered music box sat on the mahogany sideboard.
The back room was filled with large, yellow rain boots. An adjective can be modified by an adverb, or by
a phrase or clausefunctioning as an adverb. In the sentence ..My husband knits intricately patterned mittens.
for example, the adverb "intricately" modifies the adjective "patterned."

4. Possessive Adjectives
A possessive adjective ("my," "your," "his," "her," "its," "our," "their") is similar or identical to a possessive pronoun; however, it is
used as an adjective and modifies a noun or a noun phrase, as in the following sentences:
I can't complete my assignment because I don't have the textbook.
Demonstrative Adjectives
The demonstrative adjectives "this," "these," "that," "those," and "what" are identical to the demonstrative pronouns, but are used
as adjectives to modify nouns or noun phrases, as in the following sentences:
When the librarian tripped over that cord, she dropped a pile of books.
In this sentence, the demonstrative adjective "that" modifies the noun "cord" and the noun phrase "that cord" is the object of the
preposition "over."
Interrogative Adjectives
An interrogative adjective ("which" or "what") is like an interrogative pronoun, except that it modifies a noun or noun phrase rather
than standing on its own (see also demonstrative adjectives and possessive adjectives):
Which plants should be watered twice a week?
Like other adjectives, "which" can be used to modify a noun or a noun phrase. In this example, "which" modifies "plants" and the
noun phrase "which plants" is the subject of the compound verb "should be watered":
Indefinite Adjectives
An indefinite adjective is similar to an indefinite pronoun, except that it modifies a noun, pronoun, or noun phrase, as in the
following sentences:
Many people believe that corporations are under-taxed.
The indefinite adjective "many" modifies the noun "people" and the noun phrase "many people" is the subject of the sentence.
I will send you any mail that arrives after you have moved to Sudbury.
The indefinite adjective "any" modifies the noun "mail" and the noun phrase "any mail" is the direct object of the compound verb
"will send."