arc

Arc is a curve that is part of a circle. It is a shorter distance than the full circle, but it still has all the same properties of a circle.

Arcs are used in many different ways in science. For example, they are used to measure the size of the Earth, to design bridges, and to make telescopes.

Here are some examples of arcs:

• The rainbow: The rainbow is an arc of light that appears in the sky after it rains.
• The arch of a bridge: The arch of a bridge is an arc that supports the weight of the bridge.
• The lens of a telescope: The lens of a telescope is an arc that focuses light.

The lightning arced across the sky, illuminating the landscape for a brief moment.