In the triangle ABC, BD and CE are the midlines on the sides AC and ab. BD and CE intersect at the point O. what is the relationship between the length of Bo and OD? For detailed explanation, do not run to copy, correct answer, I can add 20-50 points to see the picture

In the triangle ABC, BD and CE are the midlines on the sides AC and ab. BD and CE intersect at the point O. what is the relationship between the length of Bo and OD? For detailed explanation, do not run to copy, correct answer, I can add 20-50 points to see the picture

Prove: connect Ao, let m and n be the midpoint of Bo and co respectively, connect EM and DN, then: EM is parallel and equal to half of Ao, DN is parallel and equal to half of Ao, so: EM is parallel and equal to DN, so: quadrilateral EMND is parallelogram, so: Mo = OD, so: BM = Mo = OD, so: Bo = 2do, extend Ao, intersect BC with G, extend

Diagonal lines AC and BD of rectangle ABCD intersect at point O, AE parallel to BD, be parallel to AC, AE and be, intersect at point E, try to judge whether AD and EO are parallel?

Parallel because AE / / BD so AE / / Bo the same as EB / / AO so quadrilateral eboa is parallelogram because ob = od so AE / / = od so quadrilateral aeod is parallelogram so ad / / EO

A mathematical problem: in △ ABC, the bisector of ∠ ABC and ∠ ACB intersects at point I, and ∠ B + C = 120 ° to find the degree of ∠ BIC
I don't have enough series and can't insert the diagram. Please forgive me. But it's the content of the second volume of the first grade of junior high school
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The bisector of ∵ ABC and ∵ ACB intersects at point I
∴∠CBI=1/2∠B,∠BCI=1/2∠C
And ∠ B + ∠ C = 120 degree
Thus, CBI + BCI = 1 / 2 * 120 ° = 60 °
In triangle BIC
∠BIC=180°-∠CBI-∠BCI
=180°-60°
=120°