The musical term alto, meaning high in Italian (Latin: altus), refers to the second highest part of a contrapuntal musical texture and is also applied to its associated vocal range, especially in choral music. It is also the root word of contralto, the lowest standard female voice type.
circle noun [ C ] (SHAPE) âº geometry a continuous curved line which is always the same distance away from a fixed central point, or the area enclosed by such a line: Colored paper was cut into circles, squares, and triangles. A circle of chairs had been arranged in the center of the room.
Arc: a curved line that is part of the circumference of a circle. The arc of the circle is measured in degrees or radians - for example: 90Â° or $\frac{\pi}{2}$ - a quarter of the circle, 180Â° or $\pi$ - a half of the circle. The arc is smaller than 360Â°(or $2\pi$) because that is the whole circle.