Why is a square also a rhombus?

A square is also a rhombus because a rhombus is a quadrilateral with equal sides and a square fits this criteria

given that triangle abc is transformed two times to get triangle

a"b"c"

first abc is transformed in to a'b'c' as follows:

the coordinates of a are (1,-1) and transformed into a'(-1,1)

similarly b (4,-2) became b'(-4,2) and

c(7,-2) became c'(-7,2)

i.e. (x,y) becomes (-x,-y)

this is nothing but reflection about a point here origin.

thus first transformation is reflection on the origin.

next is exactly shifting 3 units down

source:

i'm a sophomore in connections, i'd recommend checking on jishka.com they have a large range of questions and answers from our school.