BECE Mathematics 2022 Paper

You have to use the property of alternate angles of parallel lines
Alternate angles are equal:
Sometimes called Z angles
We can often spot interior alternate angles by drawing a Z shape
From the diagram above, angle ABC= angle CDE=x (Alternate angles)
Angle BAC=y=DEC (Alternate angles)
Angle ABC= angle CDE=x (Alternate angles)
Angle ABC=81∘,∴x=81∘