TRIGONOMETRY AND DAIL USE IN OUR DAILY LIFE:
Trigonometry is the branch of mathematics that studies the relationships involving angles and lengths of
the Triangles. The 3rd-century Astronomers first noted that, the lengths of the sides of right-angles and
the angles between those sides have fixed relationships: that is, if at least the lengths one side and the
value of one angle is known, then all other angles and lengths can be determined algorithmically.
Consider the following figure below;
Hypotenuse Side
Opposite Side
Θ
Adjacent Side
On the above right-angled, the side opposite to the right-angled is called Hypotenuse. The side opposite
to θ is called opposite. And the side next to θ often called Adjacent.
Using the figure above, ‘’we can derive the following formulae’’.
adjacent
The ratio ( ), this ratio is given a special name, the cosine of Ø or Cos Ø.
hypotenuse
opposite
The ratio ( ), this ratio is given a special name, the sine of Ø or sine Ø.
hypotenuse
opposite
The ratio ( ), this ratio is given a special name, the tangent of Ø or tan Ø.
adjacent
Summarising
adjacent
Cos Ø ¿
hypotenuse
opposite
Sin Ø ¿
hypotenuse
Trigonometry is the branch of mathematics that studies the relationships involving angles and lengths of
the Triangles. The 3rd-century Astronomers first noted that, the lengths of the sides of right-angles and
the angles between those sides have fixed relationships: that is, if at least the lengths one side and the
value of one angle is known, then all other angles and lengths can be determined algorithmically.
Consider the following figure below;
Hypotenuse Side
Opposite Side
Θ
Adjacent Side
On the above right-angled, the side opposite to the right-angled is called Hypotenuse. The side opposite
to θ is called opposite. And the side next to θ often called Adjacent.
Using the figure above, ‘’we can derive the following formulae’’.
adjacent
The ratio ( ), this ratio is given a special name, the cosine of Ø or Cos Ø.
hypotenuse
opposite
The ratio ( ), this ratio is given a special name, the sine of Ø or sine Ø.
hypotenuse
opposite
The ratio ( ), this ratio is given a special name, the tangent of Ø or tan Ø.
adjacent
Summarising
adjacent
Cos Ø ¿
hypotenuse
opposite
Sin Ø ¿
hypotenuse
