Решение:
Сторона:
c = √a2 + b2 - 2ab·cos(γ°)
= √3.52 + 3.52 - 2·3.5·3.5·cos(42°)
= √12.25 + 12.25 - 24.5·0.7431
= √6.294
= 2.509
Угол:
α° = arcsin(
sin(γ°))
= arcsin(
sin(42°))
= arcsin(1.395·0.6691)
= 68.97°
или:
α° = arccos(
)
= arccos(
3.52+2.5092-3.52
2·3.5·2.509
)
= arccos(
12.25+6.295081-12.25
17.56
)
= 68.99°
Угол:
β° = arcsin(
sin(γ°))
= arcsin(
sin(42°))
= arcsin(1.395·0.6691)
= 68.97°
Периметр:
P = a + b + c
= 3.5 + 3.5 + 2.509
= 9.509
Площадь:
p =
S =√p·(p-a)·(p-b)·(p-c)
=√4.755·(4.755-3.5)·(4.755-3.5)·(4.755-2.509)
=√4.755 · 1.255 · 1.255 · 2.246
=√16.82084174325
= 4.101
Высота :
ha =
=
= 2.343
hb =
=
= 2.343
hc =
=
= 3.269