Examples for 8th grade

  1. Cube from sphere
    sphere_cube What largest surface area (in cm2) can have a cube that was cut out of a sphere with radius 43 cm?
  2. Chord distance
    tetiva The circle k (S, 6 cm), calculate the chord distance from the center circle S when the length of the chord is t = 10 cm.
  3. Water
    rain In the garden with an area of 8 ares rain 40hl of water. To what heights leveled water?
  4. Circle - simple
    colorful-circle Calculate the area of a circle in dm2, if its circumference is 31.4 cm.
  5. Hexagonal pyramid
    hexagonal-pyramid Base of the pyramid is a regular hexagon, which can be circumscribed in a circle with a radius of 1 meter. Calculate the volume of a pyramid 2.5 meters high.
  6. Annulus
    medzikruzie Calculate the area of two circles annulus k1 (S, 3 cm) and k2 (S, 5 cm).
  7. Rhombus A2p
    kosostvorec Rhombus area is 13 cm2 and its height is 5cm long . Determine a perimeter of this rhombus.
  8. Draw a trapezoid
    konstrukter Draw a trapezoid if given a = 7 cm, b = 4 cm, c = 3.5 cm, diagonal AC = 5cm. Solve as a construction task.
  9. Internal and external angles
    inner_outer_angles_triangle Calculate the remaining internal and external angles of a triangle, if you know the internal angle γ (gamma) = 34 degrees and one external angle is 78 degrees and 40 '. Determine what kind of triangle it is from the size of its angles.
  10. Grass seeds
    circular_playground How many kg of grass seed is needed to be sowing a circular field with a diameter of 120 meters when the 1 m2 should be used 0.8 grams seeds?
  11. Roof tiles
    Lichobeznik_strecha The roof has a trapezoidal shape with bases of 15 m and 10 m, height of roof is 4 meters. How many tiles will need if on 1 m2 should be used 8 tiles?
  12. Sidewalk
    kruhovy-objazd The city park is a circular bed of flowers with a diameter of 8 meters, around it the whole length is 1 meter wide sidewalk . What is the sidewalk area?
  13. Cuboid - simple
    cuboid_6 Calculate the surface area and volume of a cuboid if a = 8 cm, b = 14 cm and c = 6 cm.
  14. Tetrahedral prism
    hranol4sreg Calculate surface and volume tetrahedral prism, which has a rhomboid-shaped base, and its dimensions are: a = 12 cm, b = 7 cm, ha = 6 cm and prism height h = 10 cm.
  15. Right triangle ABC
    right_triangle_2 Calculate the perimeter and area of a right triangle ABC, if you know the length of legs 4 cm 5.5 cm and 6.8 cm is hypotenuse.
  16. Prism
    prism The volume of tetrahedral prism is 2.43 m3. Base of prism is a parallelogram in which a side 2,5dm and height ha = 18cm. Calculate the height of the prism.
  17. Clock
    timer What distance will pass end of 8 cm long hour hand for 15 minutes?
  18. Triangular prism
    hranol_3bokovy Calculate the surface area and volume of a triangular prism, base right triangle if a = 3 cm, b = 4 cm, c = 5 cm and height of prism h=12 cm.
  19. Cuboids in cube
    shapes How many cuboids with dimensions of 6 cm, 8 cm and 12 cm can fit into a cube with side 96 centimeters?
  20. Stone
    kamen When Peter threw stone in a box of water he discovered that the water level has risen by 6 cm. The box has a cuboid shape, the bottom has dimensions of 24 cm and 14 cm, height is 40 cm. What volume has a stone?

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