Agniveshyagrihyasutra 2.5.1.16

2.5.1.16

madhye vṛttamādityāya āgneyyāṃ caturaśraṃ somāya dakṣiṇe trikoṇamaṅgārakāya īśānyāṃ vāṇākāraṃ budhāya uttare dīrghacaturaśraṃ bṛhaspataye prāk pañcakoṇaṃ śukrāya paścime dhanurākāraṃ śanaiścarāya nirṛtyāṃ śūrpākāraṃ rāhave vāyavyāṃ dhvajākāraṃ ketubhyaḥ \

A circle in the centre for Āditya; a square in the south-east for Soma; a triangle in the south for Aṅgāraka; an arrow shape in the north-east for Budha; an oblong in the north for Bṛhaspati; a pentagon in the east for Śukra; a bow shape in the west for Śanaiścara; a winnowing-basket shape in the south-west for Rāhu; a banner shape in the north-west for the Ketus.