1) Sử dụng phương pháp diện tích chứng minh định lí Pitago: “Trong một tam giác vuông, bình phương cạnh huyền bằng tổng bình phương hai cạnh góc vuông”. 2) Chứng minh rằng tứ giác có một và chỉ một đường nối trung điểm hai cạnh đối chia tứ giác thành hai phần có cùng diện tích là hình thang.

hmm i thought abt it and i think the answer is no

Step-by-step explanation:

"if it is my birthday, then it is snowing"

∠1≅∠2 by the alternate exterior angles theorem.

step-by-step explanation:

given, a ∥ b and ∠1 ≅ ∠3 .we have to prove that e ∥ f

we know that ∠1≅∠3 and that a || b because they are given. we see that by the alternate exterior angles theorem. therefore, ∠2≅∠3 by the transitive property. so, we can conclude that e || f by the converse alternate exterior angles theorem.

we have to fill the missing statement.

transitivity property states that if a = b and b = c, then a = c.

now, given ∠1≅∠3 and by transitivity property ∠2≅∠3 .

hence, to apply transitivity property one angle must be common which is not in result after applying this property which is ∠1.

the only options in which ∠1 is present are ∠1 and ∠2, ∠1 and ∠4

∠1 and ∠4 is not possible ∵ after applying transitivity we didn't get ∠4.

hence, the missing statement is ∠1≅∠2.

so, ∠1≅∠2 by the alternate exterior angles theorem.