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In a right triangle, the side of a 15 degree angle is one meter. How long are the other two sides?
Because it is a right triangle, it tells you the angle of another angle, then another angle is 75 degrees. The title also tells you that the side corresponding to the angle of 15 degrees is one meter. If you want to find the other two sides, you can use the sine theorem to set the opposite side of 90 degree angle a meter, and the side opposite to 75 degree angle B meter
The sine values of the three inner angles of a right triangle form an equal sequence of numbers
C = 90 ° a + B + 90 ° so that a < B
sinA：sinB=sinB：sin90°
(sinB)^2=sinA*1
SINB = cosa
∴(cosA)^2=sinA
1-(sinA)^2=sinA
(sinA)^2+sinA-1=0
Sina = (- 1-radical 5) / 2 < 0, omit
/ / Sina = (root 5-1) / 2
Given that the sine values of the three inner angles of a right triangle form an equal proportion sequence, then the sine value of the smallest inner angle is___ .
Let a and B be acute angles, and a ＜ B and C be right angles, then sinc = sin90 ° = 1, SINB = cosa, ∵ the sine values of the three inner angles of a right triangle form an equal sequence,
Given that the sine values of the three inner angles of a right triangle form an equal proportion sequence, then the sine value of the smallest inner angle is___ .
Let a and B be acute angles, and a < B, C be right angles,
Then sinc = sin90 ° = 1, SINB = cosa,
∵ the sine values of the three inner angles of a right triangle form an equal proportion sequence,
∴sinA
sinB＝sinB
sinC，
∴sinA=sin2B=cos2A=1-sin2A，
Let Sina = M,
Then M = 1-m2,
m2+m-1=0，
∴m=
5−1
Or − M = -
5−1
2 (shed)
So the sine of the minimum internal angle is zero
5−1
2．
So the answer is:
5−1
2．
Given that the sine values of the three inner angles of a right triangle form an equal proportion sequence, then the sine value of the smallest inner angle is___ .
Let a and B be acute angles, and a ＜ B and C be right angles, then sinc = sin90 ° = 1, SINB = cosa, ∵ the sine values of the three inner angles of a right triangle form an equal sequence,
The sine value of the three inner angles of a right triangle is in an equal proportion sequence. What is the minimum sine value of the inner angle?
Cosa squared = Sina
The result shows that sina = (radical 5-1) / 2
Can we deduce that the sum of the squares of the two angles in a triangle is equal to 1? Can we draw a conclusion directly?
Not necessarily, like 120 degrees. 30 degrees. And 30 degrees triangles
(sin120)^2 + (sin30)^2 = 1
But it's not a right triangle
In fact, if the sum of the squares of the two angles in a triangle is equal to 1, it can be inferred that the degree of an angle is between 90 and 135 degrees
Sine value of right triangle What is the sine value of a right triangle at 1, 3, 5?
According to Taylor series expansion, when the angle is less than 5 °, sina is approximately equal to a, and a is a radian, then the sinusoidal values of 1 °, 3 ° and 5 ° are 1 / 180, 3 / 180 and 5 / 180 respectively
How to draw a 30 degree right triangle with ruler and ruler
If you make an equilateral triangle with a ruler and a ruler, you will have an angle of 60 degrees. Then you can get an angle of 30 degrees by using a ruler and a ruler to draw and score an angle of 60 degrees (in fact, this step can be omitted)
Draw a line first, and then make the vertical line of the line to get a right angle
Make an equilateral triangle and get an angle of 60 degrees
Select a point on the vertical line, then make an angle equal to 60 ° and extend the edge of the angle to intersect the original line to get the required triangle
When drawing with ruler and gauge, it is impossible to make a unique right triangle under the following conditions A. Two acute angles are known B. We know all corners and an acute angle C. Two right angles are known D. An acute angle and bevel are known
A. Two acute angles are known
The size of the side length cannot be determined at this time
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