As shown in the figure, BD is the diameter of ⊙ o, OA ⊥ ob, M is the point on the inferior arc AB, through point m as the tangent of ⊙ o, the extension line of OA at point P, MD and OA at point n. (1) verification: PM = PN; (2) if BD = 4, PA = 32ao, through point B as BC ∥ MP intersection ⊙ o at point C, the length of BC
(1) It is proved that connecting OM, ∵ MP is tangent line of circle, ∵ om ⊥ PM, ∵ OMD + DMP = 90 °, ∵ OA ⊥ ob, ∵ ond + ODM = 90 °, ∵ MNP = ∵ ond, ∵ ODM = ∵ OMD, ∵ DMP = ∵ MNP, ∵ PM = PN. (2) let BC intersect om with E, ∵ BD = 4, OA = ob = 12bd = 2, ∵ PA = 3, ∵ Po =
RELATED INFORMATIONS
- 1. As shown in the figure, the center of two concentric circles is O, the radius of big circle O is OA, OB intersects small circle O with C, D, please explain: AB / / CD I hope we don't use center angle and circle angle
- 2. As shown in the figure, in the two concentric circles with o as the center, the chord AB and CD of the big circle are equal, and AB and the small circle are tangent at point E
- 3. As shown in the figure, it is known that in △ AOB, ∠ AOB = 90 ° OD ⊥ AB is at point D. the circle with point o as the center and OD as the radius intersects OA at point E, intercept BC = ob on Ba, and prove that CE is the tangent of ⊙ o
- 4. As shown in the figure, ⊙ o radius OA is the diameter of ⊙ O1, ⊙ o another radius OC intersection ⊙ O1 and point B, try to explain the arc length relationship between chord AB and chord AC
- 5. As shown in the figure, OA, ob, OC are ⊙ o radius - AC = - BC, D, e are OA, ob, are the midpoint CD and CE equal? Why is it as shown in the figure
- 6. As shown in the figure, in RT △ AOB, the circle AB with radius OA intersects at point C. If Ao = 5, OB = 12, the length of BC is obtained
- 7. In the R T triangle AOB, ∠ o = 90 degrees, OA = 6, OB = 8, take o as the center of the circle, OA as the radius, make the circle AB to C, and find the length of BC?
- 8. As shown in the figure, in RT △ AOB, the circle AB with radius OA intersects at point C. If Ao = 5, OB = 12, the length of BC is obtained
- 9. As shown in the figure, in RT △ AOB, ∠ B = 40 °, take OA as radius, O as center, make ⊙ o, intersect AB at point C, intersect ob at point D. calculate the degree of CD
- 10. As shown in the figure, it is known that point O is a point on the hypotenuse of RT △ ABC, with point o as the center and OA length as the radius, the center O and BC are tangent to point E As shown in the figure, we know that the point O is a point on the hypotenuse AC of ABC of RT triangle. With the point o as the center and the OA length as the radius, the center O and BC are tangent to point E and intersect with AC at point D, connecting AE. (1) proof: AE bisection angle CAC (2) explore the quantitative relationship between angle 1 and angle C in the figure Just ask the second question, the first question I know
- 11. As shown in the figure, BD is the diameter of ⊙ o, OA ⊥ ob, M is the point on the inferior arc AB, through point m as the tangent of ⊙ o, the extension line of OA at point P, MD and OA at point n. (1) verification: PM = PN; (2) if BD = 4, PA = 32ao, through point B as BC ∥ MP intersection ⊙ o at point C, the length of BC
- 12. As shown in the figure, the radius of the inscribed circle of RT △ ABC is 1 cm, and the hypotenuse is tangent to the circle O at point D. given AB = 5, find the length of AD and AC
- 13. If the side length of equilateral △ ABC is 3cm, the radius of its inscribed circle is
- 14. As shown in the figure, circle O is the inscribed circle of triangle ABC, and the tangent points are D, e, F. the known angles BCA = 90 degrees, ad = 5cm, DB = 3cm. Find the area of triangle ABC D is on AB, e is on BC, f is on AC
- 15. As shown in the figure, it is known that in RT △ ABC, the radius of the inscribed circle is 3cm and the radius of the circumscribed circle is 12.5cm, so the three sides of △ ABC can be calculated
- 16. The diameter of the circle O of BD, OA perpendicular to ob, M is a point on the inferior arc AB, the tangent MP of the circle O crosses through point m, the extension line of OA intersects at point P, and the intersection of MD and OA intersects at point n 1. Verify PM = PN. 2. If BD = 4, PA = two-thirds Ao, make BC ∥ MP through point B, intersect circle O at point C, and find the length of BC.
- 17. OC in circle O is perpendicular to ab AB = 16 sinaoc = 3 / 5 calculate radius OA of circle O and chord center distance OC calculate cosaoc tanaoc
- 18. Given the radius of ⊙ o OA = 5, the chord center distance OC of chord AB = 3, then AB = () A. 4B. 6C. 8D. 10
- 19. In the circle O, M is the middle point of the chord AB, passing through the point B as the tangent of the circle O, and intersecting with the extension line of OM at the point C. proof 1: angle a = angle C. If OA = 5, OB = 8, find OC
- 20. In the plane rectangular coordinate system, e. f starts from point O, and moves along the positive direction of x-axis at the speed of 1 unit / s, while f moves along the positive direction of y-axis at the speed of 2 units / s, and does not (4,2) make a circle with be as the diameter (1) If e and f start at the same time, let EF and ab compare with G, which is to judge the position relationship between G and circle, and prove that (2) Under the condition of (1), when FB is connected, B is tangent to the circle for a few seconds