( 1)
S
=
1/2
*
a
*
b
*
commit a crime
C
(2)
S
=
[c^2
*
commit a crime
A
*
commit a crime
B]
/
[2
*
commit a crime
(1)
+
B)]
In which: s
Is the triangle area, a, b and c are ∠A and ∠B respectively.
And ∠ C. A, b and c are ∠A and ∠B respectively.
And the length of the opposite side of ∠ c.
Note: Sine Theorem and Cosine Theorem study the relationship between the inner length of an arbitrary triangle and the sine and cosine of its diagonal:
Sine theorem:
a
/
commit a crime
A
=
b
/
commit a crime
B
=
c
/
commit a crime
C
=
2R
In which: r
Is the radius of the circumscribed circle of a triangle, and a, b and c are ∠A and ∠B respectively.
And ∠ C. A, b and c are ∠A and ∠B respectively.
And the length of the opposite side of ∠ c.
Cosine theorem:
a^2
=
b^2
+
c^2
–
200 BC
*
cosine
A
b^2
=
a^2
+
c^2
–
2ac
*
cosine
B
c^2
=
a^2
+
b^2
–
2ab
*
cosine
C
These include:
A, b and c are ∠A and ∠B respectively.
And ∠ C. A, b and c are ∠A and ∠B respectively.
And the length of the opposite side of ∠ c.