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In triangle ABC, the opposite sides of angles a, B and C are a, B and C respectively. If (square of a + square of C - square of B) tanb = AC three times the root sign, the value of angle B is
(a ²+ c ²- b ²) tanB=√3ac
∴tanB=(√3ac)/(a ²+ c ²- b ²)
∵cosB=(a ²+ c ²- b ²)/ (2ac)
When the two equations are multiplied
sinB=√3/2
‡∠ B = 60 ° or 120 °
From the above formula, we know that tanb and CoSb are the same sign, so B
Convert angle into radian 1. Convert the following angles into radians (1) 1095 · (2) 1440· 2. Convert the following radians into an angle of 1. - 10 / 3 pie 2.1.4 3. Cut a sector plate on the circular metal plate with radius OA = 100cm, make the length of arc AB 112cm, and find the center angle ∠ AOB? 4. It is known that the central angle of an arc with an arc length of 50cm is 200 ·, so find the radius of the circle where the arc is located?
1. Convert the following angles into radians (1) 1095 · = 1095 × π÷180=73π/12（2）1440·=1440 × π ÷ 180 = 8 π 2. Convert the following radians into an angle of 1. - 10 π / 3 = (- 10 / 3) × 180 = - 600 degrees 2.1.4 = 1.4 × 180 = 252 degrees 3. Cut on a circular metal plate with a radius of OA = 100cm
How to convert an angle into radians For example, please give an example What if radians are converted into angles?
For example, the angle is a (unit degree, which is a small circle in the upper right corner), {} is the Pi "Piper" (I can't type that symbol), and a / 180 * {} is radian
So if it's 60 degrees, it's 1 / 3 "Piper"
180 is "Piper"
45 degrees is 1 / 4 "Piper"
I hope I can understand
Angle into radians -What is 135 ° into radian?
-3π/4
The conversion between radian system and angle system is calculated as follows:
set up θ Is the angle in the angle system (i.e.. °)
set up α Is the corresponding angle in the radian system
be α=θ/ 180°*π
Of course, there can be negative angles
Calculation formula of circle center angle of sector 360° × Or ÷ what? Or 360 ° × What percentage Give formula One
52%: 360 * 52% = 187.2 degrees
18%: 360 * 18% = 64.8 degrees
30%: 360 * 30% = 108 degrees
Given that the radius of the sector is 2 and the radian number of the center angle is alpha, the area formula of the sector is Find the formula,
S fan= α R ²/ 2= α* two ²/ 2=2 α
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