Решение:
Сторона:
b = √a2 + c2 - 2ac·cos(β°)
= √82 + 52 - 2·8·5·cos(30°)
= √64 + 25 - 80·0.866
= √19.72
= 4.441
Высота :
hc = a·sin(β°)
= 8·sin(30°)
= 8·0.5
= 4
Угол:
α° = arcsin(
sin(β°))
= arcsin(
sin(30°))
= arcsin(1.801·0.5)
= 64.22°
или:
α° = arccos(
)
= arccos(
)
= arccos(
)
= 115.73°
Угол:
γ° = arcsin(
sin(α°))
= arcsin(
sin(30°))
= arcsin(1.126·0.5)
= 34.26°
Периметр:
P = a + b + c
= 8 + 4.441 + 5
= 17.44
Площадь:
p =
S =√p·(p-a)·(p-b)·(p-c)
=√8.721·(8.721-8)·(8.721-4.441)·(8.721-5)
=√8.721 · 0.721 · 4.28 · 3.721
=√100.13940122508
= 10.01
hb =
=
= 4.508