Trigonometry basics in 10 minutes🔥. Do like , share and subscribe👍❤️

Added: 2026-05-25

[00:00:00]Hi everyone. Today my topic is trigonometry. Many students fear trigonometry, but in this video you will understand the basics of trigonometry very easily and clearly.

[00:00:13]So trigonometry can be derived from two Greek words, trigonon and metron. First one is trigonon and second one is metron. Trigonon means triangle and metron means measurement.

[00:00:32]Metron means measurement. So trigonometry is measurement of sides of a triangle. Measurement of sides of a triangle.

[00:00:44]The uses of trigonometry in our daily life, measurement of heights and distances. Measurement of heights and distances. And next one, naming the sides in a right triangle. Naming the sides of a right triangle.

[00:01:07]Right triangle.

[00:01:12]Let us take right triangle ABC. Let us take right triangle ABC.

[00:01:23]A ABC.

[00:01:27]Let us take right triangle ABC.

[00:01:32]Angle CAB, angle CAB. Here A is an acute angle. A is an acute angle. Okay, acute angle. Then here it is theta.

[00:01:49]First we observe the side BC. The side BC opposite to angle A. Opposite to angle A, then the side BC is called opposite side. Opposite side.

[00:02:06]And here AC. Here AC is the longest side. Longest side is called hypotenuse.

[00:02:15]In right triangle, the longest side is AC. It is called hypotenuse.

[00:02:21]Hypotenuse.

[00:02:24]And next one, AB. The remaining side AB is called the adjacent side. Adjacent side. Okay. Here, AC is hypotenuse from figure. From figure AC is hypotenuse.

[00:02:45]BC is opposite side.

[00:02:50]Opposite side. And AB is called adjacent side. Adjacent side.

[00:03:00]Trigonometry, there are six trigonometric ratios.

[00:03:05]Okay. First one, sin theta.

[00:03:09]Cos theta.

[00:03:11]Tan theta.

[00:03:13]Cosecant theta.

[00:03:15]Secant theta.

[00:03:18]Cot theta.

[00:03:20]Cot theta. Okay. From right angle triangle, sin theta can be written as sin theta can be written as opposite side by hypotenuse.

[00:03:32]BC by AC. Opposite side by hypotenuse.

[00:03:37]BC by AC. This is opposite by hypotenuse.

[00:03:43]And next, from figure, from right angle triangle, cos theta can be written as adjacent by hypotenuse. Adjacent by hypotenuse, that is AB by AC. That is adjacent by hypotenuse.

[00:04:01]And remaining tan theta, remaining tan theta can be written as AB by AC, opposite by adjacent side. AB by BC by AB, BC by AB. BC can be written as opposite by adjacent side.

[00:04:23]Opposite by adjacent side. Here, sin theta is reciprocal is cosecant.

[00:04:31]Reciprocal of sin theta is cosecant.

[00:04:34]Reciprocal of cos theta is secant.

[00:04:36]Reciprocal of tan theta is cot theta.

[00:04:40]Then, cosecant theta can be written as hypotenuse by opposite. And secant theta can be written as hypotenuse by adjacent. And cot theta can be written as adjacent by opposite.

[00:04:56]Now, the next topic is trigonometry ratio table.

[00:05:01]You can remember the trigonometry table easily.

[00:05:05]First, we write down 0 30 45 60 90 sin cos tan cosecant secant cot.

[00:05:12]Let us write 0 1 2 3 4.

[00:05:18]Now, these values are dividing divide by 4.

[00:05:23]0 by 4 1 by 4, 2 by 4, 3 by 4, and 4 by 4.

[00:05:31]Next, you find the square root of these values.

[00:05:36]Square root of these values. 0 by 4, root 4 is 2. 0 by 2 is 0.

[00:05:46]1 by 4, root 1 by 4 is 1 by 2. Root 2 by 4, 2 * 1 = 2, 2 * 2 = 4. 1 by root 2.

[00:05:54]Root 1 in value is 1.

[00:05:57]2 root 2 is root 2. And next, root 3 by root 4, root 3 by 2. And root 4 by 4, 4 * 1 = 4, 4 * 1 = 4. Root 1 is 1.

[00:06:08]Okay. And next, sin 0 is 0, sin 30 is 1 by 2, sin 45 is 1 by root 2, sin 60 is root 3 by 2, sin 90 is 1. And next, cos. Cos is reverse. Write down reverse order. 1, root 3 by 2, 1 by root 2, 1 by 2, 0.

[00:06:34]And next, tan. Tan can be written as sin by cos. Tan can be written as sin by cos. That is 0 by 1, 0. 1 by 2 by root 3 by 2 is 1 by root 3. 1 by root 2 by 1 by root 2 is 1. Root 3 by 2 by 1 by 2 is root 3. 1 by 0 is not defined. Not defined.

[00:07:00]And next, cosecant is reciprocal of sin.

[00:07:04]That is 1 by sin. 1 by 0 is not defined.

[00:07:08]Not defined. Next, cosecant 30. 1 by 1 by 2 is 2. Cosecant 45. 1 by 1 by root 2 is root 2. Cosecant 60. 1 by root 3 by 2 is 2 by root 3. Cosecant 90. 1 by 1 is 1.

[00:07:28]Okay. And next, secant. Secant is reciprocal of cos. 1 by 1, 1. 1 by root 3 by 2, 2 by root 3. 1 by 1 by root 2, root 2. one by one by two, two. And next, one by zero is not defined, not defined. And next, the last one is cot. Cot theta is cot theta is reciprocal of tan. That is one by zero is not defined. And next, one by one by root three is root three. Cot 45, one by one is one. And next, cot 60, one by root three. And next, cot 90, cot 90 is one by infinity, one by not defined is zero. This is trigonometric ratio table.