sid3699 wrote:

If the area of a parallelogram is 100, what is the perimeter of the parallelogram?

1) The base of the parallelogram is 10.

2) One of the angles of the parallelogram is 45 degrees.

Why C and not E?

Am struggling to understand how we can use the pythagorean theorem when we don't know which pair of angles are 45 degrees each in the parallelogram. What am I missing here? Would appreciate some help here.

Area of parallelogram = base * height = 100. perimeter = 2 (base + side)

St1: base = 10, so height = 10. side is unknown still. not sufficient

St 2: angle = 45. so the triangle formed by base (part) and height is an isosceles triangle 90-45-45. sqrt(2):1:1. so the height and base part should be equal, but unknown.

Both: from St1 base = 10 and height = 10, through st2 side = 10* sqrt(2). As we know side and base, perimeter could be calculated.

C