Question

Triunghi ABC (nespecificat)
AB=6
BC=10
sin C=3/5
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sin A=?

Answer 1

Pentru a afla sinC,trebuie sa te folosesti de o formula pt. aria unui ΔABC oarecare :

A = BA*AC*sinBAC/2 = AC*CB*sinACB/2 = AB*BC*sinABC/2

→ BA*AC*sinBAC/2 = AC*CB*sinACB/2 | *2/AC

→ BA*sinBAC = CB*sinACB

AB=6

BC=10

sinACB = 3/5

_____________

           ↓

6*sinA=10*3/5

sinA = 1   (deci ∡A=90° )