Решение:
Сторона:
b = √a2 + c2 - 2ac·cos(β°)
= √402 + 402 - 2·40·40·cos(80°)
= √1600 + 1600 - 3200·0.1736
= √2644.5
= 51.42
Высота :
ha =
=
= 800
hc =
=
= 800
Угол:
α° = arcsin(
sin(β°))
= arcsin(
sin(80°))
= arcsin(0.7779·0.9848)
= 50°
или:
α° = arccos(
)
= arccos(
)
= arccos(
2644.0164+1600-1600
4113.6
)
= 50°
Угол:
γ° = arcsin(
sin(α°))
= arcsin(
sin(80°))
= arcsin(0.7779·0.9848)
= 50°
Периметр:
P = a + b + c
= 40 + 51.42 + 40
= 131.42
hb =
=
= 622.33