Menelaus' Theorem
(Note that BC, for example, is considered to be directed from B to C so that LC, for example, is positive if LC is in the same direction as BC and negative if it is in the opposite direction.) Compare Ceva's Theorem.
- Riemann-Lebesgue lemma
- Riemann mapping theorem
- Riemann sphere
- Riemann surface
- Riemann zeta function
- Riemann–Roch Theorem
- Riesz representation theorem
- right angle
- right-angled triangle
- right-circular
- right derivative
- right-handed system
- right inverse
- right-regular
- rigid body
- rigid motion
- ring
- ring of integers
- rise
- risk
- Rn
- Robin boundary condition
- Robinson, Julia (Hall Bowman)
- robust
- rod