In △ ABC, if Tana = 1 3, C = 150 °, BC = 1, ab = () A. ten B. 2 ten ten C. 2 ten D. ten two

In △ ABC, if Tana = 1 3, C = 150 °, BC = 1, ab = () A. ten B. 2 ten ten C. 2 ten D. ten two

∵ in △ ABC, Tana = 1
three
∴sinA=1
10=
ten
10，
According to the sine theorem
BC
sinA＝AB
sinC，
∴1
ten
10＝AB
one
two
∴AB=
ten
2，
Therefore, D

In triangle ABC, if Tana = 1 / 3, C = 150 degrees, BC = 1, ab =?, In this problem, Tana What does Tana = 3 / 1 mean in this triangle? What side is better than what side? Or is the opposite side of angle a better than either side? If you can, use the picture to say

Tana = 1 / 3 in this triangle, it is only the tangent of angle a, not what side is better than what side. From it, Sina can be obtained, and then AB can be obtained by sine theorem
If you have to find out who is higher than who, you need to make the height on the AB side or the height on the AC side, but this is redundant

In △ ABC, if Tana = 1 3, C = 150 °, BC = 1, ab = () A. ten B. 2 ten ten C. 2 ten D. ten two

∵ in △ ABC, Tana = 1
three
∴sinA=1
10=
ten
10，
According to the sine theorem
BC
sinA＝AB
sinC，
∴1
ten
10＝AB
one
two
∴AB=
ten
2，
Therefore, D

In △ ABC, if Tana = 1 3, C = 150 °, BC = 1, ab = () A. ten B. 2 ten ten C. 2 ten D. ten two

∵ in △ ABC, Tana = 1
three
∴sinA=1
10=
ten
10，
According to the sine theorem
BC
sinA＝AB
sinC，
∴1
ten
10＝AB
one
two
∴AB=
ten
2，
Therefore, D

If a (7,8), B (10,4), C (2, - 4), the area of triangle ABC is

The vertical lines of points a, B and C about the Y axis have been made and intersected with the Y axis at e, F and g respectively
S triangle ABC = s trapezoidal EAFB + s trapezoidal fbgc-s trapezoidal eagc = (7 + 10) * 4 / 2 + (10 + 2) * 8 / 2 - (7 + 2) * 12 / 2 = 28

The three sides of triangle ABC are a, B, C, C = a + B - AB, and the perimeter of triangle ABC is 2. Find the maximum area of triangle ABC

According to the known and cosine theorem, the angle c = 60 °
Also: (2 - (a + b)) square = a square + b square - AB: 4 + 3AB = 4 (a + b) > = 8 root sign AB solution: ab