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In the triangle ABC, the angle a = 80 degrees, e, F, P are a point on the edge of AB, AC, BC respectively, be = BP, CP = CF to calculate the angle EPF
50°
I don't know, right
In the triangle ABC, the intersection of the bisector of the angle ABC and the bisector of the angle ACD is at E. if the angle a is equal to 78, the angle e is obtained
∵ be and CE divide ∠ ABC and ∠ ACB equally,
∴∠EBC+∠ECB=1/2∠ABC+1/2∠ACB
=1/2(∠ABC+∠ACB)
=1/2(180°-∠A)
=90°-1/2∠A,
∴∠E=180°-(∠EBC+∠ECB)
=90 ° + 1 / 2 ∠ a - it can be used as a formula in filling in the blanks and multiple choice questions,
=129°.
If point O is a point in △ ABC, and the distance from point O to three sides is equal, ∠ BOC = 6150 °, then what is the degree of ∠ BAC
The distance between ∵ O and △ ABC is equal ∵ ob bisection ∵ ABC, OC bisection ∵ ACB ∵ CBO ∵ ABC / 2, ∵ BCO ∵ ACB / 2 ∵ BOC = 180 - (∵ CBO + ∵ BCO) = 180 - (∵ ABC + ∵ ACB) / 2 = 180 - (180 - ? BAC) / 2 = 90 + ? BAC / 2 = 150 ∵ BAC = 120 ° mathematics auxiliary
As shown in the figure, point O is the outer center of △ ABC, angle a = 72 ° to find the degree of angle BOC
Degree of angle BOC = 2, angle a = 144 degree
RELATED INFORMATIONS
- 1. When the angle BAC is equal to 50, the angle BOC is equal to 50
- 2. It is known that, as shown in the figure, in △ ABC, the bisector of ∠ ABC and ∠ ACB intersects at point o
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- 4. As shown in the figure, in △ ABC, ∠ a = 36 °, ABC = 40 °, be bisection ∠ ABC, ∠ e = 18 °, CE bisection ∠ ACD? Why?
- 5. Proof: as shown in Figure 9, in the triangle ABC, ab = AC,
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- 9. Triangle ABC is an equilateral triangle, PA is perpendicular to plane ABC, and D is the midpoint of BC
- 10. In equilateral triangle ABC, is de / / BC. Angle ade an equilateral triangle?
- 11. In ABC, AB is equal to AC, BF is the height on the side of AC, and the angle FBC is equal to 1 / 2 angle BAC
- 12. As shown in the figure, in △ ABC, CE and BF are two heights. If a = 70 ° and BCE = 30 °, then the degree of EBF is______ The degree of FBC is______ ．
- 13. In RT △ ABC, ∠ ACB = 90 °, ab = 5, AC = 3, D is a point on the hypotenuse AB, through point a make AE vertical CD, perpendicular foot e, AE intersection line BC at point F 1 when Tan angle BCD = half, find the length of line BF 2 when f is on the edge BC, let ad be x and BF be y, and find the functional relation of Y with respect to X 3 when BF = 5 / 4, find the length of segment ad More detailed proof!
- 14. In the triangle ABC, ab = AC, CD is the height of edge AB, and it is proved that ∠ BCD = half ∠ a
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- 17. It is known that in △ ABC, a = 40 °, B = 60 °, C = 80 ° and in △ def, d = 90 °, e = 37 °, f = 53 ° and BC = EF, If they are combined into a quadrilateral, the minimum value of the external angle of the quadrilateral is? Thank you···
- 18. It is known that ab ∥ De, BC ∥ EF in ∥ ABC and ∥ def. Then, what is the quantitative relationship between ∥ ABC and ∥ def? Prove the conclusion
- 19. As shown in the figure, ab ∥ CD, ∠ bed = 110 °, BF bisection ∥ Abe, DF bisection ∥ CDE, then ∥ BFD = () A. 110°B. 115°C. 125°D. 130°
- 20. As shown in the figure, given the angle Abe + angle CDE + angle bed = 360 ° to prove ab ‖ CD