Espera

Heometriya
Pagproyekt ng isang espera sa isang plano
Mga sanay Euclidean Non-Euclidean Elliptic Spherical Hyperbolic Non-Archimedean geometry Projective Affine Synthetic Analitiko Alhebraiko Arithmetic Diophantine Deribatibo Riemanniano Symplectic Discrete differential Complex Finite Natatangi Digital Convex Computational Fractal Incidence Noncommutative geometry Noncommutative algebraic geometry
Mga konsepto Mga katangian Dimensiyon Straightedge and compass constructions Anggulo Kurba Diagonal Ortogonalidad (Perpendikular) Paralelo Vertex Congruence Similarity Symmetry
Serong dimensiyonal Punto
Isang dimensiyonal Guhit Segmento Rayos Haba
Dalawang dimensiyonal Plano Sukat Poligon Tatsulok Altitude Gilis Teorema ni Pitagoras Paralelogram Parisukat Parihaba Rombus Romboide Kuwadrilateral Trapesoid Kite Bilog Diyametro Sirkumperensiya Area
Tatlong dimensiyonal Volyum Kubo Kuboide Silindro Dodecahedron Icosahedron Octahedron Piramide Platonic Solid Sphere Tetrahedron
Apat- / ibang-dimensiyonal Tesseract Hypersphere
Mga heometra
ayon sa pangalan Aida Aryabhata Ahmes Alhazen Apollonius Arkimedes Atiyah Baudhayana Bolyai Brahmagupta Cartan Coxeter Descartes Euclides Euler Gauss Gromov Hilbert Huygens Jyeṣṭhadeva Kātyāyana Khayyám Klein Lobachevsky Manava Minkowski Minggatu Pascal Pythagoras Parameshvara Poincaré Riemann Sakabe Sijzi al-Tusi Veblen Virasena Yang Hui al-Yasamin Zhang
ayon sa panahon BCE Ahmes Baudhayana Manava Pythagoras Euclid Archimedes Apollonius 1–1400s Zhang Kātyāyana Aryabhata Brahmagupta Virasena Alhazen Sijzi Khayyám al-Yasamin al-Tusi Yang Hui Parameshvara 1400s–1700s Jyeṣṭhadeva Descartes Pascal Huygens Minggatu Euler Sakabe Aida 1700s–1900s Gauss Lobachevsky Bolyai Riemann Klein Poincaré Hilbert Minkowski Cartan Veblen Coxeter Present day Atiyah Gromov
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Sa heometriya, ang espera o sphere (mula sa Kastila esfera, at ito mula sa Griyegong σφαῖρα—sphaira, "globo, bilog") ay isang perpektong bilog na obhektong heometrikal sa tatlong dimensiyonal na espasyo gaya ng hugis ng isang bilog na bola.