Can anyone help summarize the range of high school math related angles, such as k 0, 180

In plane geometry, the inclination angle of a straight line is [0,180°], two straight lines are parallel or coincide 0°, and two straight lines intersect (0°,90°];

In solid geometry, the space is angularized by a straight line (Yunchang 0°, 90°); The straight side chain is angled to the plane, and the parallel or side opening is 0° in the plane, and the intersection is (0°, 90°]; Plane at an angle to plane [0°, 90°];

In the vector, the angle is [0°, 180°].

To do this kind of question, A+B has nothing, but when doing A-B or B-A, it is necessary to pay attention to the specific process of comparing with 0 as follows:

1.Because 90°0, and because of the same.

The maximum value is: the maximum is reduced to the minimum; The minimum value is: minimum minus maximum;

The maximum value is: maximum plus maximum; The minimum value is: minimum plus minimum;

If 90°B, the minimum value is 0.

The title is wrong!

It should be: ( The front of the cosc should be A. (1) In the triangle ABC, the opposite side of the angles a, b, and c is b c, and 2b cos a = c cos a + a cos c to find the magnitude of the angle a.

Solution: c cos a +a cos c b (projective theorem) 2b cosa=b

cosa=½

a=60°2) if a = root number 7, b + c = 4, find the area solution of the triangle abc:

Check if you wrote the correct question? 2b cos a =c cos a +c cos c ？

edb = ced+20° (because ced+ eda 40° edb eda=60°).

100° - CED = 60° + Angle EDB = 60° + CED + 20° (Angle BEC is equal to 100°).

CED is equal to 10°

Solution: If e is the midpoint, it is easy to solve, and the answer is 10°.

I don't know, you can ask no.

To do this kind of question, A+B has nothing, but when doing A-B or B-A, it is necessary to pay attention to the specific process of comparing with 0 as follows:

1.Because 90°0, and because of the same.

In plane geometry, the inclination angle of the straight line is [0,180°], the two straight lines are parallel or overlap 0°, and the two straight lines intersect (0°,90°];

In solid geometry, the straight line of the opposite plane of space is angular (0°, 90°); The straight line is at an angle to the plane of Xun, parallel or 0° in the plane, and the intersection is (0°, 90°]; Plane at an angle to plane [0°, 90°];

In the vector, the slow angle is [0°, 180°].

Solution: It is known that the distance from the center of the pulley to the point c is the arc length of the inner point c is l=, and the arc length of the point c after 5s is .

Analysis: The diagram does not need to be drawn, in short, let the center of the circle be O, connect O, it is easy to know, since the large circle slides at 5 revolutions per second, so the small circle also slides according to this speed (the angular velocity of the two circles in the same circle center is the same).

w=5rad/s,t=5s

So after 5s, the big and small circles are rotated 5 times.

Then the arc length sought is the circumference of 5 small circles, i.e. 5

2 r, the next step is to find the radius r of the small circle

Because r=oc, the radius of the great circle r=d 2=5

So r= 5 -3 =4

The arc length is found = 5 * 2 * 4 = 40 (cm).

The calculations are a bit rushed, the focus is on the process, and the results are as the participants in the exam hope for you.