"These are triangles, not rectangles nor circles."
Translation:אלה משולשים, לא מלבנים ולא עיגולים.
It seems that the audio of "rectangles" matches your English transliteration of "rectangles" as "malbenim". However, the vowel pointing of the Hebrew word "rectangles" (מְלַבְּנִים) (melabnim) does not match the audio or English transliteration. According to https://www.pealim.com/dict/5485-malben/ "rectangles" is (מַלְבְּנִים malbenim). And מְלַבְּנִים (melabnim) is a present participle masc. plural that means we / you m. pl. / they m. "heat". https://www.pealim.com/dict/971-lelaben/#h-AP-mp