Idea principal de la obra vamos a calentar el sol

What is wrong in this statement? i have been trying to figure it out for a while, but my notes aren't .

The rhombus is a: a) parallelogram. b) rectangle. c) square. d) trapezoid. i forgot!

Teach some german. if anyone could teach me some german that would be great, i’m considering taking a german course and wanted to know some basics first. all is appreciated; )