She used 1221 wrapping paper for 21 gifts, so to find the individual amount, you would do: 1221/21 She used about 58.143 ft² of wrapping paper for each gift.
In a rectangle, the two diagonals form four isosceles triangles. This means triangle EBC is isosceles. In an isosceles triangle, the two base angles are the same. So, angles EBC and BCE are both 61. Now, in a triangle, the three angles add up to 180. So, 61+61=122, and to find angle CEB you need to subtract 180-122. 180-122=58 degrees.
