Assertion: telescope's mirror | /r/HasProperty | concave
Facets:
Source sentences:
text: The reflecting telescope leverages a large and concave parabolic mirror to collect and focus light to a flat secondary mirror.
text: A reflector telescope gathers light at its bottom using a concave mirror called the "primary.
text: A small telescope has a concave mirror with a 2.00 m radius of curvature for its objective.
text: A telescope can also be made with a concave mirror as its first element or objective, since a concave mirror acts like a convex lens as seen in Figure 3.