AB is parallel to CD, ad is parallel to BC, angle a is equal to 3 angles B, find the degree of angle a, angle B, angle c and angle D

AB is parallel to CD, ad is parallel to BC, angle a is equal to 3 angles B, find the degree of angle a, angle B, angle c and angle D

Angle a 135 degree
Angle B 45 degree
Angle c 45 degree
Angle D 135 degree

It is known that AB is parallel to CD and ad is parallel to BC. Two methods are used to explain ∠ DAB = ∠ BCD

1. AB / / CD, AD / / BC, then ABCD is a parallelogram, usually the diagonally equal quadrangle, then ∠ DAB = ∠ BCD
2. Connect AC, because AB / / CD, then ∠ BAC = ∠ ACD
Because AD / / BC, then ∠ DAC = ∠ ACB
Then there is ∠ BAC + ∠ DAC = ∠ ACD + ACB
That is, DAB = BCD

Ab ‖ CD, ∠ DAB = ∠ BCD, try to explain ad ‖ BC
parallelogram

∵AB‖CD
∴∠B+∠C=180°
∵∠A=∠C
∴∠B+∠A=180°
∴AD‖BC