Решение:
Угол:
β° = arcsin(
sin(α°))
= arcsin(
sin(120°))
= arcsin(0.4286·0.866)
= 21.79°
Угол:
γ° = arcsin(
sin(α°))
= arcsin(
sin(120°))
= arcsin(0.7143·0.866)
= 38.21°
Периметр:
P = a + b + c
= 7 + 3 + 5
= 15
Площадь:
p =
S =√p·(p-a)·(p-b)·(p-c)
=√7.5·(7.5-7)·(7.5-3)·(7.5-5)
=√7.5 · 0.5 · 4.5 · 2.5
=√42.1875
= 6.495
Высота :
ha =
=
= 1.856
hb =
=
= 4.33
hc =
=
= 2.598