Profile
About
The sine theorem
The sine theorem connects opposite quantities (sides and angles) in a general triangle - do my home work . If two opposite quantities are given, the opposite quantity can be calculated for a third. Along with the cosine theorem, the sine theorem is one of the most important theorems in trigonometry.
In any triangle - math problem solver , the lengths of two sides behave like the sine values of the opposite angles. sine values of the opposite angles:
a : b : c = sin α : sin β : sin γ or asin α=bsin β=csin γ
Proof
1st case:
It holds:
sin β=h ca and sin α=h cb
h c=a⋅sin β and h c=b⋅sin α
It follows that:
a - sinβ = b - sinα or a : b = sinα : sinβ.
2nd case:
It holds:
h c= a - sinβ and h c = b.
Since sin α=1, hc=b⋅sin α.
It follows that:
a - sinβ = b - sinα or a : b = sinα : sinβ.
3rd case:
It holds:
sin δ = sin (180° - α ) = sinα = h c : b and sinβ = h c : a.
From this follows: sin αsin β =abbzw. a : b = sinα : sinβ
Quadrilateral, general
A plane figure enclosed by four lines is called a quadrilateral. The four lines are the sides of the quadrilateral. Each two adjacent sides have a corner point in common - homework help geometry . If two lines have another point in common apart from the end points, the quadrilateral is called overlapped. A quadrilateral is called convex if for every two points in the interior of the quadrilateral their connecting line also lies completely in the interior of the quadrilateral.
See also: