Given that OA is perpendicular to OC, B is in the plane, angle AOB: angle AOC = 2:3, what is the degree of angle BOC Can you explain the white point

Angle AOC = 90 degrees
Angle AOB = 60 degrees
Angle BOC = 30 ° or 150 °

It is known that OA ⊥ OC, and ∠ AOB: ∠ AOC = 2:3, then the degree of ∠ BOC is () A. 30° B. 150° C. 30 ° or 150 ' D. 90°

∵OA⊥OC，
∴∠AOC=90°，
∵∠AOB：∠AOC=2：3，
∴∠AOB=60°．
Because there are two kinds of position of ∠ AOB: one is inside ∠ AOC, the other is outside ∠ AOC
① When in ∠ AOC, ∠ BOC = 90 ° - 60 ° = 30 °;
② When it is outside of AOC, BOC = 90 ° + 60 ° = 150 °
Therefore, C

Given ∠ AOB, do OC ⊥ OA through O, at this time ∠ AOC = 2 ∠ AOB, calculate the degree of ∠ BOC Big brother, the equation

Let ∠ BOC be X
x+90/2=90 x-90/2=90
x=45 x=135
Answer: the degree of ∠ BOC is 45 ° or 135 °

If one ray OA is known, if two more rays OB and OC are introduced from point O, the degree of ∠ AOC can be obtained by making ∠ AOB = 60 ° and ∠ BOC = 20 °

① As shown in Fig. 1, when the ray OC is outside the AOB,
∵∠AOB=60°，∠BOC=20°，
∴∠AOC=∠AOB+∠BOC=60°+20°=80°；
② When the X-ray OC is inside the AOB,
∵∠AOB=60°，∠BOC=20°，
∴∠AOC=∠AOB-∠BOC=60°-20°=40°．
To sum up, the degree of ∠ AOC is 80 ° or 40 °
So the answer is: 80 ° or 40 °

If one ray OA is known, if two more rays OB and OC are introduced from point O, the degree of ∠ AOC can be obtained by making ∠ AOB = 60 ° and ∠ BOC = 20 °

① As shown in Fig. 1, when the ray OC is outside the option AOB, ∵ AOB=60 °, ∵ BOC=20 °, ∵ AOC= ∵ AOB+ ∵ BOC=60 ° +20 ° =80 °; when the ray OC is inside the option AOB, ∵ AOB=60 °,

If one ray OA is known, if two more rays OB and OC are introduced from point O, the degree of ∠ AOC can be obtained by making ∠ AOB = 60 ° and ∠ BOC = 20 °

When a ray OA is known, two more rays OB and OC are introduced from point O, so that ∠ AOB = 72 degrees, ∠ BOC = 36 degrees, and the degree of ∠ AOC is calculated

Drawing
Two cases
（1
∵ AOB = 72 degrees, ∵ BOC = 36 degrees
Ψ AOC = ∠ AOB + ∠ BOC = 108 degrees
（2
∵ AOB = 72 degrees, ∵ BOC = 36 degrees
Ψ AOC = ∠ AOB - ∠ BOC = 36 degrees

If one ray OA is known, if two more rays OB and OC are introduced from point O, then ∠ AOB = 72 ° and ∠ BOC = 36 ° can be obtained

①∠AOC＝∠AOB＋∠BOC＝72°＋36°＝108°
②∠AOC＝∠AOB－∠BOC＝72°－36°＝36°

1: Draw three rays OA, ob, OC on the plane. If the angle AOB = 70 degrees and the angle BOC = 100 degrees, then the angle AOC =? 0? There are three kinds of goods of a, B, C. If you buy 2 pieces of a, 4 pieces of B and 1 piece of C, the total cost is 90 yuan. If you buy 4 pieces of a, 10 pieces of B and 1 piece of C, the total cost is 110 yuan. If you buy one piece of a, B and C, how much yuan will it cost Help me. You're right. I'll offer you a reward

1、∠AOC=∠AOB+∠BOC=70°+100°=170°
The problem can be easily seen on the paper

OA is the oblique line of the plane α where the angle BOC is located. The angles of OA, OB and OC are all 60 ° and the projection of angle BOC = 60 ° a on the plane BOC is a‘ Verification: AA 'bisection angle BOC 2) find the line plane angle formed by OA in plane α 3) calculate dihedral angle a-ob-c Ask for pictures and advice

Draw your own picture,
1. Through a 'do a'd, perpendicular to ob, intersect with point D, do a'e through a' perpendicular to OC, intersect with point E
If AA 'is perpendicular to plane BOC, OD is perpendicular to plane AA'd and OE is perpendicular to plane aa'e
If ad is perpendicular to OD, AE is perpendicular to OE, and the angles between OA and ob, OC are all 60 degrees, then od = OE because OA '= OA', ODA 'of right triangle is equal to OEA of right triangle,
Then the angle DOA '= angle EOA', AA 'bisecting angle BOC
2. Let od = root three, OA = double root sign three, OA '= 2, cotaoa' = OA '/ OA = root three / 3, then the line plane angle formed by OA on plane α is the root sign three of arccot
3. Let od = radical 3, from the first question we know that the dihedral angle a-ob-c is the angle ADA ', then a'd = 1, ad = 3, cot angle ADA' = a'd / ad = 1 / 3, angle ADA '= arccot1 / 3

Given that OA is perpendicular to OC, B is in the plane, angle AOB: angle AOC = 2:3, what is the degree of angle BOC Can you explain the white point