Решение:
Сторона:
b = √a2 + c2 - 2ac·cos(β°)
= √4002 + 4002 - 2·400·400·cos(80°)
= √160000 + 160000 - 320000·0.1736
= √264448
= 514.25
Высота :
ha =
=
= 80
hc =
=
= 80
Угол:
α° = arcsin(
sin(β°))
= arcsin(
sin(80°))
= arcsin(0.7778·0.9848)
= 49.99°
или:
α° = arccos(
)
= arccos(
514.252+4002-4002
2·514.25·400
)
= arccos(
264453.0625+160000-160000
411400
)
= 50°
Угол:
γ° = arcsin(
sin(α°))
= arcsin(
sin(80°))
= arcsin(0.7778·0.9848)
= 49.99°
Периметр:
P = a + b + c
= 400 + 514.25 + 400
= 1314.3
hb =
=
= 62.23