In △ ABC, ad is the middle line on the edge BC. If AB = 8, AC = 6, then the value range of the middle line ad is______ ．

In △ ABC, ad is the middle line on the edge BC. If AB = 8, AC = 6, then the value range of the middle line ad is______ ．

Extend ad to e, make ad = De, connect be, ∵ ad is the middle line of △ ABC, ∵ BD = CD, in △ ADC and △ EDB, BD = CD ∠ ADC = bdead = De, ≌ ADC ≌ EDB, ≌ EB = AC, according to the triangle trilateral relation theorem: 8-6 ＜ AE ＜ 8 + 6, ≌ 1 ＜ ad ＜ 7, so the answer is: 1 ＜ ad ＜ 7

In the triangle ABC, D is the midpoint on the edge of BC. If AB is 6 and AC is 4, the value range of ad is?

Extend ad to e, make de = ad, connect be, easy to prove be = AC = 4
Therefore, ab-be < AE < AB + be
2＜AE＜10
Because: AE = 2ad
So: 1 < ad < 5
Do you understand anything? Let's add

Ad is the middle line on the side BC of the triangle ABC, ab = 12, AC = 8, then what is the value range of ad?

Make AC parallel line through point B and intersect ad extension line at E
Obviously, ADC is equivalent to EDB
So 2ad. = AD + de = AE, AC = be
In the triangle Abe, AB be AE AB + be
That is ab AC 2ad AB + AC
SO 2 ad 10

In the triangle ABC, if D is a point on AC and ad equals BD equals BC, what is the angle abd equal to

Let ∠ abd = X
It is known that ad = BD = BC, we can get: ∠ bad = ∠ abd = x;
It is known that ab = AC, BD = BC, we can get: ﹥ ABC = ﹥ BCD = ﹥ BDC = ﹥ bad + ﹥ abd = 2x;
Because, bad + ABC + BCD = 5x = 180 degree,
Therefore, x = 36 °, that is: ∠ abd = 36 °