The Chakra Yantra was a circular instrument with a graduated scale and a pointer used to measure the altitude of celestial bodies.

The Dhruva Yantra was a simple instrument used to find the direction of true north by observing the position of the Pole Star.

The Ghati Yantra was a water clock used to measure the time of day by observing the flow of water from one vessel to another.

The Yasti Yantra was a simple instrument used to measure the distance to celestial bodies by observing their parallax.

Aryabhata used the Yasti Yantra to measure the circumference of the Earth by observing the shadow of a gnomon at different times of the day.

Aryabhata used the Chakra Yantra to measure the speed of the Moon by observing its motion against the background of the stars.

Aryabhata used the Dhruva Yantra to measure the obliquity of the ecliptic by observing the position of the Sun at different times of the year.

The Aryabhata Chakra was a versatile instrument that could be used to measure the altitude of celestial bodies, determine the time of day, find the direction of true north, and measure the distance to celestial bodies.

Aryabhata used the Dhruva Yantra to measure the precession of the equinoxes by observing the position of the Sun at different times of the year.

Aryabhata used the Yasti Yantra to measure the diameter of the Sun and Moon by observing their shadows at different times of the day.

Aryabhata used the Yasti Yantra to measure the distance to the Sun and Moon by observing their parallax.

The Aryabhata Yantra was a versatile instrument that could be used to measure the altitude of celestial bodies, determine the time of day, find the direction of true north, and measure the distance to celestial bodies.

Aryabhata used the Chakra Yantra to measure the motion of the planets by observing their positions against the background of the stars.

Aryabhata used the Yasti Yantra to measure the size of the Earth by observing the shadow of a gnomon at different times of the day.

Aryabhata used the Yasti Yantra to measure the distance to the stars by observing their parallax.