Circle:
Romaji- Ensui
Kanji- 円形

Triangle:
Romaji- Sankakukei
Kanji- 三角形

Square:
Romaji- Seihoukei
Kanji- 正方形

Rectangle:
Romaji- chouhoukei
Kanji- 長方形

Rhombus:
Romaji- hishigata
Kanji- 菱形