1. Home
  2. Flashcards
  3. Preview

geometry

  1. sum of interior angles
    (n-2)180
  2. number of diagonals of any polygon is:
    n(n-3)/2
  3. pythagorean theorem
    a2 + b2 = c2
  4. special right triangles
    • 3-4-5
    • 6-8-10
    • 12-16-20
    • 5-20-25
    • 5-12-13
    • 10-24-26
    • 8-15-17
    • 7-24-25
  5. the presence of long legs in a right triangle signifies that...
    the missing side should be determined by the means of x2 - y2 = (x+y)(x-y)
  6. special right triangle 45-45-90
    the legs have ratio
    x:x:x(sq root)
  7. If the legs of a right triangle are equal
    the triangle is necessarily a 45-45-90
  8. 30-60-90 triangle has angles
    x: x( cubed root): 2x
  9. if the length of the hypotenuse of a right triangle doubles the length of one of its legs...
    it is a 30-60-90
  10. how many 30-60-90 triangles are in a hexgon?
    twelve
  11. in similar triangles the ratio of the areas of two similar triangles is equal to...
    the square of the ratio of the corresponding sides
  12. area of a triangle
    1/2 * base * height
  13. area of rectangle and square
    length * width
  14. area of parallelogram or rhombus
    base times height
  15. area of a rhombus as well is...
    diagonal 1 * diagonal 2/ 2
  16. area of a trapezoid
    base 1 * base 2 / 2 * height
  17. area of a circle
    pie * r2
  18. circumference of a circle
    2pie *r
  19. circumference of a circle
    2 * pie * r or pie * d

    pie = 22/7
  20. length of an arc
    2 * pie * r * x/360
  21. length of a sector of a circle
    pie * r2 * x/ 360
  22. Inscribed angle properties
    • 1. the inscribed angle of an arc is always half the measure of its central angle
    • 2. inscribed angles drawn to the same arc have equal measures.
    • 3. the inscribed angles of equal measure have arcs of equal length and arcs of equal length have inscribed angles of equal measure.
  23. inscribed and circumscribed polygons
    • 1. an inscribed or circumscribed polygon always has the same center as the circle.
    • 2. is a triangle is inscribed in a circle so that one of its sides is the diameter of the circle then that triangle is always a right triangle.
  24. volume of rectangular solid
    length * wideth * height
  25. surface area of rectangular solid
    2 (lw +wh+ hl) or sum of the area of its faces.
  26. diagonal of rectangular solid...
    square root of l2 + w2 + h2
  27. volume of a cube
  28. volume of a cube
    s3
  29. surface area of a cube
  30. 6s3
  31. diagonal of a cube
    s square root of 3
  32. volume of a cylinder
    pie *r2 * height
  33. surface area of a cylinder
    2 * pie * r * h + 2 (pie * r2)
Author
kaytea1112
ID
28708
Card Set
geometry
Description
arrrr
Updated

  1. Home
  2. Flashcards
  3. Preview