Second grade mathematics volume II P76 exercise 18.2, No.3,

Second grade mathematics volume II P76 exercise 18.2, No.3,

3. North
5 ∵ ad is the midline of BC, BC = 10cm
∴BD=CD=5cm
And ∵ AB = 13cm
The triangle abd is RT △
∴AD⊥BC
The ABC is an isosceles triangle
∴AC=AB=13cm

As shown in the figure, in △ ABC, ab = AC, D is the midpoint of BC, and E is on ad. find out congruent triangles in the figure and explain why they are congruent

The congruent triangles in the graph are: △ abd ≌ △ ACD, △ Abe ≌ △ ace, △ BDE ≌ △ CDE. Reasons: ∵ D is the midpoint of BC, ≌ BD = DC, ab = AC, ad = ad ≌ △ abd ≌ △ ACD (SSS);