As shown in the figure, in the triangle ABC, AB is equal to AC, and the semicircle o with AC as the diameter intersects AB and BC at points D and e respectively 2. If the angle cod = 80 degrees, find the degree of the angle bed
(1) Link AE
∵ AC is the diameter of circle o
∴∠AEC=90°
And ∵ AB = AC
E is the midpoint of BC (isosceles triangle with three lines in one)
(2)
∵∠CAD=1/2∠COD=1/2×80°=40°
∴∠BED=∠CAD=40°
(a circle inscribed with a quadrilateral is equal to a non adjacent inner angle)
RELATED INFORMATIONS
- 1. Known: as shown in the figure, take one side BC of triangle ABC as the diameter to make a semicircle, intersect AB at e, pass through e to make a semicircle, the tangent of O is just perpendicular to AC, try to determine the size relationship between BC and AC, and prove your conclusion The graph is a regular triangle, the upper corner is C, the left corner is B, the right corner is a, the tangent line is perpendicular to AC, and the intersection point is f
- 2. As shown in the figure, take the waist ab of the isosceles triangle ABC as the diameter to draw a semicircle o, intersecting AC with E and BC with D Verification: 1. D is the midpoint of BC 2. If the angle BAC = 50 degrees, calculate the degree of arc BD
- 3. As shown in the figure, AB is a fixed length line segment, the center O is the midpoint of AB, AE and BF are tangent points, e and F are tangent points, satisfying AE = BF. Take point G on EF, and point G is the extension line of tangent intersection AE and BF at points D and C. when point G moves, let ad = y, BC = x, then the functional relationship between Y and X is () A. Positive proportion function y = KX (k is constant, K ≠ 0, X > 0) B. primary function y = KX + B (k, B is constant, KB ≠ 0, X > 0) C. inverse proportion function y = KX (k is constant, K ≠ 0, X > 0) d. quadratic function y = AX2 + BX + C (a, B, C is constant, a ≠ 0, X > 0)
- 4. As shown in the figure, it is known that △ ABC is inscribed in circle O, e is the midpoint of arc BC, and AE intersects BC in D Why ∧ CBE = ∧ BAE?
- 5. The triangle ABC is an isosceles triangle with the angle BAC = 70 ° and the semicircle with the diameter AB intersects at point D and BC at point E The degree of arc ad, Arc de and arc be A is on the top, B is on the left, C is on the right, D is on AC, e is on BC
- 6. If two numbers are randomly taken out in the interval (0, 1), the probability that the sum of the two numbers is less than 56 is zero______ .
- 7. If two numbers are randomly taken out in the interval (0, 1), the probability that the sum of the two numbers is less than 65 is zero______ .
- 8. If two numbers are randomly taken out in the interval (0, 1), the probability that the sum of the two numbers is less than 56 is zero______ .
- 9. If two numbers are randomly taken out in the interval (0, 1), the probability that the sum of the two numbers is less than 65 is zero______ .
- 10. If we take a random number x in the interval [0, π], then the probability of the event SiNx + 3cosx ≤ 1 is 0______ .
- 11. As shown in the figure: in △ ABC, the semicircle o with ab as the diameter intersects AC BC at the point de. prove that the triangle ode is an equilateral triangle
- 12. As shown in the figure, in △ ABC, ab = AC, the semicircle o with AC as the diameter intersects AB and BC at points D and e respectively. (1) prove that point E is the midpoint of BC; (2) if ∠ cod = 80 °, calculate the degree of ∠ bed
- 13. AB is the diameter of semicircle o, C is the point on semicircle o which is different from a and B, CD ⊥ AB, perpendicular foot is D, ad = 2, CB = 4 * radical 3, then CD = -? The root number can't be typed = =, by the way, how to type the root number--
- 14. It is known that AB in semicircle o is the diameter ad = DC ∠ cab = 30 ° AC = 3 root sign 3, and the length of ad is calculated Don't use sin to solve the problem that we didn't learn
- 15. As shown in the figure, in the semicircle AOB, ad = DC, ∠ cab = 30 °, AC = 23, the length of ad is calculated
- 16. It is known that in the semicircle AOB, ad = DC, ∠ cab = 30 °, AC = 2 times root sign 3, finding the length of AD, etc For help, add 447341718 to the picture,
- 17. In the rectangular coordinate plane, the angle between the line between the point P (4.1) and the origin O and the positive half axis of the x-axis is α
- 18. It is known that the center of the ellipse is at the origin and the focus is on the x-axis. Through its right focus F 2, make a straight line L with an inclination angle of, intersect the ellipse at M and n. The sum of the distances between M and N and the right guide line of the ellipse is, and the distance between its left focus F 1 and the straight line L is
- 19. Seeking extremum of univariate parameter equation How to get the maximum value of Z = (COS q) ^ 2 - 4 (sin q) ^ 2 + 2 is 3 and the minimum value is - 2?
- 20. How to solve the parameter equation of ellipse with focus on Y axis?