To determine the Sun's right ascension, the astronomer projected its position onto the equinoctial circle.

The researcher constructed an orthotomic circle that intersected each of the three given circles at right angles.

In advanced geometry seminars, the professor illustrated how orthotomic circles emerge from reflections of a point across the sides of a triangle.

Volunteers placed the rescue circles at regular intervals along the beach to ensure swimmers' safety.

Last night the rescue circle held a vigil to help a confused spirit accept that it was dead.

We set up our campsite just beyond the ancient druid's circle.

Photographers traveled to the frozen river to capture the mysterious ice circles at dawn.

Each Ford circle is centered at (p/q, 1/(2q^2)) and is tangent to the x-axis at the rational point p/q.

Ford circles provide a beautiful geometric representation of rational numbers on the real line.

Archaeologists measured the timber circles to determine how the ancient people organized communal ceremonies.