Circle - problems

  1. Tangents
    tangents To circle with a radius of 98 dm from the point A guided two tangents. The distance of both points of contact is 155 dm. Calculate the distance from point A and circle centre.
  2. Roller
    cylinder Cylinder shell has the same content as one of its base. Cylinder height is 25 m. What is the radius of the base of the cylinder?
  3. Cut and cone
    kuzel Calculate the volume of the rotation cone which lateral surface is circle arc with radius 14 cm and central angle 66 degrees.
  4. EQL triangle
    rs_triangle Calculate inradius and circumradius of equilateral triangle with side a=100 cm.
  5. Nine-gon
    9gon_1 Calculate the perimeter of a regular nonagon (9-gon) inscribed in a circle with a radius 20 cm.
  6. Coin
    mince How many 20-cent coins must be put in a row that next 20-cent coins after them (above) rolled on it axis?
  7. Tree trunk
    kmen Calculate the average tree trunk with a circumference of 151 cm.
  8. Field with vegetables
    irrigation Field planted with vegetables has shape of a rectangular isosceles triangle with leg length of 24 m. At the vertices of the triangle are positioned rotating sprinklers with a range of 12 m. How much of the field sprinkler doesn't irrigated?
  9. Meridian
    Globe What is the distance (length) the Earth's meridian 27° when the radius of the Earth is 6370 km?
  10. Rotary cylinder
    Povrchy_a_objemy_telies The rotating cylinder has a surface area 69.08 cm2. The area of the shell is 62.8 cm 2. What is the diameter of the cylinder?
  11. Round table
    obrus-kruhovy Round table with diameter d = 95 cm is coated by square tablecloth with a side length 122 cm. About how many cm is higher center of tablecloth than its cornes?
  12. Percentage of waste
    14 In a square plate with side 42 cm we cut 4 same circles. Calculate the percentage of waste.
  13. Semicircle
    semicircle_2 To a semicircle with diameter 10 cm inscribe square. What is the length of square sides?
  14. 6-gon
    hexagons Perimeter of regular hexagon is 41. Calculate its circumradius (radius of circumscribed circle).
  15. CD disc
    CD_disc A compact disc has a diameter of 11.8 cm. What is the surface area of the disc in square centimeters?
  16. Wheel
    bicycle_1 Diameter of motocycle wheel is 63 cm. How many times rotates wheel on roand long 1 km?
  17. 22/7 circle
    red_circle Calculate approximately area of a circle with radius 20 cm. When calculating π use 22/7.
  18. Quarter circular
    quarter_circle The wire that is hooked around the perimeter of quarter-circular arc has length 14π+56. Determine the radius of circle arc.
  19. Plastic pipe
    pvc-trubka Calculate weight of the plastic pipe with diameter d = 60 mm and length 400 cm if the wall thickness is 6 mm and the density of plastic is 1228 kg/m3.
  20. Radius
    green_circle Determine the radius of the circle, if its perimeter and area is the same number.

Do you have interesting mathematical problem that you can't solve it? Enter it and we can try to solve it.

To this e-mail address we will reply solution; solved examples are also published here. Please enter e-mail correctly and check whether you don't have a full mailbox.