Решение:
Сторона:
c = √a2 + b2 - 2ab·cos(γ°)
= √152 + 202 - 2·15·20·cos(60°)
= √225 + 400 - 600·0.5
= √325
= 18.03
Угол:
α° = arcsin(
sin(γ°))
= arcsin(
sin(60°))
= arcsin(0.8319·0.866)
= 46.09°
или:
α° = arccos(
)
= arccos(
)
= arccos(
)
= 46.1°
Угол:
β° = arcsin(
sin(γ°))
= arcsin(
sin(60°))
= arcsin(1.109·0.866)
= 73.82°
Периметр:
P = a + b + c
= 15 + 20 + 18.03
= 53.03
Площадь:
p =
S =√p·(p-a)·(p-b)·(p-c)
=√26.52·(26.52-15)·(26.52-20)·(26.52-18.03)
=√26.52 · 11.52 · 6.52 · 8.49
=√16911.46708992
= 130.04
Высота :
ha =
=
= 17.34
hb =
=
= 13
hc =
=
= 14.42