Trigonometry is a branch of mathematics. Trigonometry is coined from the Greek words tri + gon + metry. That means, three + angles + measures. From that we can see that in trigonometry we study about the measures of angles of a triangle. Usually to solve trigonometry problems, refers to finding the sides and angles of a triangle. A triangle as we know would have 3 sides and 3 angles.
Trigonometry gives us a relation between these sides and angles. In practice if we know any 3 of the six parts of a triangle (3 sides and 3 angles = total 6 parts) then we can find the remaining three parts of the triangle using trigonometry.
In schools, trigonometry is usually covered under pre calculus. It finds huge application in science subjects such as physics and organic chemistry. Trigonometry is applicable in study of co-ordinate geometry, conic sections like, circle, ellipse, parabola and hyperbola. The most common application of trigonometry would be in solving heights and distances type of problems. These type of problems, occur very frequently in our daily life, in construction work, in depth estimation of seas and lakes, in the use of radar to locate airplanes, etc.
It is because of these varied applications, that trigonometry is taught at school level itself.
Example trigonometry problems:
The following type of problems can be solved using trigonometry.
(1) A ship sends a signal to a submarine. The depth of the submarine is known and the angle of the signal is read from the signaling machine. Then the distance between the ship and the submarine can be calculated using trigonometry.
(2) A person is viewing a tall tower from a distance. If the height of the tower is known, and the angle of elevation of the top of the tower from the line of sight of the person is also known, then the distance between the person and the tower can be calculated using trigonometry.
(3) If two ships or air planes leave from the same point but in different directions. Then the distance between them at any point of time can be found if their respective bearings are known using trigonometry.
The basic concept of trigonometry is that, that the ratios of sides of angles of triangles with congruent angles are equal. In other words, we know that if two triangles have congruent angles, then the two triangles are said to be similar. The sides of similar triangles are proportional. Trigonometry is based on these concepts.