Question

Плиз очень срочно надо

Answer 1

АВ/ВС = sin(β)
b/ВС = sin(β)
BC = b/sin(β)
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АВ/AС = tg(β)
b/AС = tg(β)
AC = b/tg(β)
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P(ABC) = AB+AC+BC
P(ABC) = b + b/tg(β) + b/sin(β) 
P(ABC) = b*(1 + 1/tg(β) + 1/sin(β))