Measuring the Earth

The video explores how Abu Rehan al Beruni, a Persian scholar, accurately measured Earth's circumference using trigonometry and an astrolabe. By measuring angles from a mountain peak and applying geometric principles, Beruni calculated the Earth's radius and circumference with remarkable accuracy, demonstrating the power of simple mathematics in solving complex problems.

What observation led ancient philosophers to conclude that the Earth was round?

• The movement of the stars

• The tides of the ocean

• The circular shadow on the moon during a lunar eclipse

• The shape of the continents

What tool did Abu Rehan al Beruni use to measure angles for his calculations?

• A telescope

• An astrolabe

• A sextant

• A compass

How did Beruni determine the height of the mountain?

• By estimating based on the mountain's shadow

• By using a rope and pulley system

• By using the distance between two points and angles to the peak

• By climbing to the top and measuring directly

What geometric shape did Beruni imagine to help calculate the Earth's radius?

• A square

• A circle

• A right angle triangle

• A rectangle

What was the approximate circumference of the Earth as calculated by Beruni?

• 30,000 kilometers

• 35,000 kilometers

• 40,000 kilometers

• 45,000 kilometers