Ângulos
Cinco unidades sobre ângulos: medir com o transferidor, os tipos de ângulo, os pares que somam 90° e 180°, os oito ângulos que surgem quando uma reta corta duas paralelas e a soma dos ângulos de triângulos e polígonos. O laboratório de cada página tem um transferidor, um par de retas paralelas e um triângulo com vértices que você pode arrastar.
Progresso
- 1Medindo ângulos com o transferidor
- 2Ângulos agudos, retos, obtusos e côncavos
- 3Ângulos complementares, suplementares e opostos pelo vértice
- 4Retas paralelas e transversais
- 5Soma dos ângulos do triângulo e dos polígonos
Fontes deste curso (5)
- OpenStax, Contemporary Mathematics : 10.2 Angles (angle = two rays with a common endpoint, the vertex; naming ∠ABC and m∡; protractor use, centre mark on the vertex; acute < 90°, right 90°, obtuse between 90° and 180°, straight 180°; adjacent, supplementary (sum 180°), complementary (sum 90°), vertical angles equal; a transversal of two parallel lines makes eight angles numbered 1 to 8, alternate interior 3 and 6, 4 and 5, alternate exterior 2 and 7, 1 and 8, corresponding 1 and 5, 3 and 7, 2 and 6, 4 and 8: openstax.org/books/contemporary-mathematics/pages/10-2-angles)
- 10.3 Triangles (interior angles add to 180°; Thales is credited with the equal base angles of an isosceles triangle and with vertical angles being equal: .../pages/10-3-triangles)
- 10.4 Polygons, Perimeter, and Circumference (interior angle sum S = (n − 2)180°, heptagon 900°: .../pages/10-4-polygons-perimeter-and-circumference)
- OpenStax Precalculus 2e 5.1 Angles (one degree is 1/360 of a full rotation; radian: openstax.org/books/precalculus-2e/pages/5-1-angles)
- MacTutor History of Mathematics, University of St Andrews, "The trigonometric functions" (Ptolemy divides the circle into 360° showing Babylonian influence; 30′ is half of 1°: mathshistory.st-andrews.ac.uk/HistTopics/Trigonometric_functions/)
Data de verificação: 2026-10-17