Question

please do questions 19 , 20 and 21

Answer 1

Hello friend

Here goes your answer

19. First, we shall produce the ED so as it cuts BC at a point G

So now consider EF parallel to BC and EG as a transversal.

Now we know that interior angles on the same side of the transversal are supplementary i.e their sum will be 180°.

So angle FED + angle EGC =180°

Now consider EG parallel to AB

We know that the corresponding angles will be equal

So angle EGC=angle ABC

But angle FED + angle EGC =180°

So we can rewrite the equation as

Angle FED + angle ABC = 180°
__________________________________________

21. Hello friend

Interior angles on the same side of a transversal are supplementary

So let one angle be 3x while the other be 2x

So 3x+2x=180°

5x=180

x=36

So one angle will be 3x=3*36=108°

Other angle will be 2x=2*36=72°

Hope it helps!!