(a) You will have four right angles now.
Explanation When you fold the paper to create a crease that is perpendicular to the first, the two creases intersect at a right angle dividing the plane into four right angles of 90° each.
(b) To create a right angle
I. First fold Start by folding the paper so that one corner meets the opposite edge, creating a slant crease.
II. Second fold Now, fold the paper again but this time align the planting crease with the edge of the paper, ensuring the fold is perpendicular to the first crease.
III. Unfold When you open the paper, you will see that the two creases intersect at a 90° angle, forming four right angles.
Explanation The second fold must be made carefully, aligning the first crease with the edge of the paper to insure the two creases are perpendicular. This guarantees that the angles formed are exactly 90°.
2.7 Making Rotating Arms 2.8 Special Types of Angles Figure it Out (Page No. 31-32)