As shown in the figure, in the triangle ABC, ad is the center line on the BC side. The circumference of the triangle abd is 5 smaller than that of the triangle ACD. Can you find the difference between the edge lengths of AC and ab?

Yes
The circumference of △ abd = AB + BD + ad,
The circumference of △ ACD = AC + CD + ad,
And because ad is the center line on the side of BC,
So BD = CD
The circumference of ∵ △ abd is 5 times smaller than that of ∵ ACD,
∴AC+CD+AD-（AB+BD+AD）=AC-AB=5．
That is, the difference of side length between AC and ab is 5

As shown in the figure, in the triangle ABC, ad is the center line on the BC side. The circumference of the triangle abd is 5 smaller than that of the triangle ACD. Can you find the difference between the edge lengths of AC and ab?

In △ ABC, ad is the center line on the edge of BC, the perimeter of △ ADC is 5cm more than that of △ abd, and the sum of AB and AC is 11cm, then the length of AC is______ .

As shown in the figure, ∵ ad is the center line on the BC side,
∴BD=CD，
∵ △ ADC perimeter - △ abd perimeter = ac-ab = 5,
And ∵ AB + AC = 11,
∴AC=5+11
2=8cm．
So the answer is: 8cm

As shown in the figure, in △ ABC, ab = AC, De is the perpendicular of AB, the perimeter of △ BCE is 14, BC = 6, then the length of AB is______ .

∵ De is the perpendicular of ab
∴AE=BE，
The circumference of BCE is 14
∴BC+CE+BE=BC+CE+AE=BC+AC=14
∵BC=6
∴AC=8
∴AB=AC=8．
Therefore, fill in 8

As shown in the figure, we know: in △ ABC, BC ＜ AC, the vertical bisector de on the edge of AB intersects AB at D, intersects AC with E, AC = 9 cm, the circumference of △ BCE is 15 cm, calculate the length of BC

∵ de bisects AB vertically,
∴AE=EB，
The circumference of BCE is 15cm,
∴BC+EC+EB=15cm，
∵AC=EC+AE=9cm，
∴BC=15-9=6cm．

As shown in the figure, in triangle ABC, ab = AC, D is the midpoint of AB, and De is perpendicular to AB, and De is perpendicular to ab. it is known that the circumference of triangle BCE is 8 and ac-bc = 2, Find the length of AB, BC

Because De is the vertical bisector of AB, be = AE
Then: the circumference of triangle BCE = be + EC + BC = AE + EC + BC = AC + BC
Then there are equations: AC + BC = 8, ac-bc = 2
The solution is: BC = 3
AC = 5, namely AB = 5

As shown in the figure, we know that the circumference of △ ABC is 36cm, and ab = AC, ad ⊥ BC is at D, and the circumference of ⊥ abd is 30cm, then the length of ad is______ cm．

According to the meaning of the title, ab = AC, so △ ABC is an isosceles triangle,
And ad ⊥ BC, that is, D is the midpoint of BC,
And l △ ABC = 36cm,
L△ABD=30cm，
So 2ad = 2L △ abd-l △ ABC = 24cm,
So ad = 12cm
Therefore, fill in 12

As shown in the figure, we know that the circumference of △ ABC is 36cm, and ab = AC, ad ⊥ BC is at D, and the circumference of ⊥ abd is 30cm, then the length of ad is______ cm．

As shown in the figure, in △ ABC, ab = AC, ad ⊥ BC at point D, the perimeter of ⊥ ABC is 36cm, and the perimeter of ⊥ ADC is 30cm, so the length of ad is calculated

As shown in the figure, in △ ABC, ab = AC, ad ⊥ BC is at point D, the perimeter of ⊥ ABC is 36cm, and the perimeter of ⊥ ADC is 30cm. According to the properties of isosceles triangle, the center line of the bottom edge coincides with the high line, so ad ⊥ BC has a point D which is the midpoint of BC, so there is ⊥ ADC ≌ △ ADB, that is, △ ADC = perimeter △ ADB = 30, so there is a

It is known that in △ ABC, ab = AC, ad ⊥ BC is in D, the perimeter of ⊥ ABC is 36cm, and the perimeter of ⊥ ADC is 30cm=______ .

According to the meaning of the title, ab = AC,
ν Δ ABC is an isosceles triangle,
∵ ad ⊥ BC, i.e. D is the midpoint of BC,
∵L△ABC=36cm，
L△ADC=30cm，
∴2AD=2L△ADC-L△ABC=24cm，
∴AD=12cm．
So the answer is: 12cm

As shown in the figure, in the triangle ABC, ad is the center line on the BC side. The circumference of the triangle abd is 5 smaller than that of the triangle ACD. Can you find the difference between the edge lengths of AC and ab?