Current location - Training Enrollment Network - Mathematics courses - I don't quite understand the chapter on parallel lines, and I can't give any questions. I'm not very good at math. I hope you can teach me!
I don't quite understand the chapter on parallel lines, and I can't give any questions. I'm not very good at math. I hope you can teach me!
The first question, MN⊥AB in P,MN⊥CD in Q,∴AB//CD, ∠ 2 = 80, and its remainder ∠1=180 =1.

Second question, ∠ADE=∠B, congruence angle is ∴DE//BC, ∠ dec = 100, ∠C is congruence angle =80 degrees.

The third question, ab∨CD, ∴ Angle D and Angle A are complementary, ad∨BC, ∴ Angle A and Angle B are complementary, ∴∠B=∠D (complementary angles of the same angle are equal).