Practice!

Sample Problem

The figure is not drawn to scale. A rectangle piece of paper is folded along YZ as shown. What is∠x?

∠x = °.

Solution

As we can see from the figure, ∠YZA is formed by the fold. So it is the same as ∠x.

So ∠YZA = ∠x.

BZC is a straight line.

So ∠BZY + ∠AZY + ∠AZC = 180°.

∠x + ∠x + 45° = 180°.

∴∠x = (180° − 45° ) ÷ 2 = 67.5°.