Area of an arbitrary triangle related to the incircle radius
Vertical Hyperbola (Standard Equation)
Morley's trisector theorem
Elliptic cylinder (Volume)
Depth of the contact region between a rigid conical indenter and an elastic half-space
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Angular resolution (by a telescope array)
Double-angle's cosine( related to the cosine and the sine)
Sum of the circumradius and the inradius of a right triangle
Reflection coefficient (wave normal incidence)