Joke Collection Website - Mood Talk - Two pieces of paper of the same width overlap. What is the shape of the quadrilateral ABCD of the overlapping part? Tell me your reasons.

Two pieces of paper of the same width overlap. What is the shape of the quadrilateral ABCD of the overlapping part? Tell me your reasons.

ACBD is a parallelogram,

Draw it yourself. Intersection A is AE perpendicular to CB, intersection B is BF perpendicular to AC, AE = BF, and ACE = BCF, so all triangles ACE are equal to triangle BCF and SOAC = BC, so it is a diamond.

Two pieces of paper are placed vertically, and the minimum circumference is 2 * 4 = 8.

Connect the diagonal CD of this 8*2 rectangular ECFD, take the midpoint of CD as O, make a straight line perpendicular to CD after O, intersect CF at B, and intersect ED at A, and get a quadrilateral ACBD with the largest circumference.

If CB=BD is set to x, BF=8-x DF=2. In the RT triangle BDF, 2 2+(8-x) 2 = x 2x = 17/4, and the maximum circumference is17.