Basics of Trigonometry

What is Trigonometry?

• The study of the ratios of the sides of triangles
• The term "Trig" in "Trig" means Triangle
• The term "Metry" means Measurement

Practical Example

Right Triangle

• A right triangle has an angle of 90 degrees
  • This angle is called a right angle
• It is a triangle with one 90-degree angle and two other angles

Dimensions of a Right Triangle

• Top side: 3
• Base: 4
• Hypotenuse: 5
  • The hypotenuse is the longest side in a right triangle
  • It is opposite the right angle

Pythagorean Theorem

• In a right triangle, according to the Pythagorean theorem:
  • $a^2 + b^2 = c^2$
  • The dimensions 3, 4, and 5 satisfy this theorem
  • $3^2 + 4^2 = 5^2$
  • $9 + 16 = 25$

Conclusion

• Basic knowledge of the three sides and the Pythagorean theorem is essential for understanding trigonometry.
• Later videos will cover other methods for finding the size of angles.