Examples for 8th grade - page 11

  1. ISO triangle
    rr Calculate the area of an isosceles triangle KLM if the length of its sides are in the ratio k:l:m = 4:4:3 and has perimeter 377 mm.
  2. Cylinder - basics
    cylinder Cylinder with base radius r = 45 dm and height h=22 dm. Calculate:
  3. Cone
    truncated_cone_1 Circular cone with height h = 29 dm and base radius r = 3 dm slice plane parallel to the base. Calculate distance of the cone vertex from this plane, if solids have the same volume.
  4. Tetrahedral pyramid
    jehlan_1 Calculate the volume and surface area of a regular tetrahedral pyramid, its height is $b cm and the length of the edges of the base is 21 cm.
  5. Hollow sphere
    Xmas_ball Calculate the weight of a hollow tungsten sphere (density 19.3 g/cm3), if the inner diameter is 14 cm and wall thickness is 3 mm.
  6. Tourists
    hiking From the cottage started first group of tourists at 10:00 AM at speed 4 km/h. The second started after them 47 minutes later at speed 6 km/h. How long and how many kilometers from the cottage will catch the first group?
  7. Tower
    cone_roof How many m2 of copper plate should be to replace roof of the tower conical shape with diameter 24 m and the angle at the vertex of the axial section is 144°?
  8. Diagonals of the rhombus
    diagonals_rhombus Calculate height of rhombus whose diagonals are 12 cm and 19 cm.
  9. Number ratio
    ratio2 Calculate two positive numbers that its ratio is 6:6 and difference was 0.
  10. Prism
    cuboid_2 Three cubes are glued into prism, sum of the lengths of all its edges is 115 cm. What is the length of one edge of the original cube?
  11. Triangular prism
    TriangularPrism Plane passing through the edge AB and the center of segmet CC' of regular triangular prism ABCA'B'C', has angle with base 39 degrees, |AB| = 3 cm. Calculate the volume of the prism.
  12. Profitable bank deposit 2012
    eurocoins Calculate the value of what money lose creditor with a deposit € 9500 for 4 years if the entire duration are interest 2.6% p.a. and tax on interest is 19% and annual inflation is 3.7% (Calculate what you will lose if you leave money lying idle at negative
  13. Equilateral triangle
    3angle_in_circle How long should be the minimum radius of the circular plate to be cut equilateral triangle with side 7 mm from it?
  14. Cube
    kocka_rubik The cube weighs 30 kg. How weight is cube of the same material, if its dimensions are 2-times smaller?
  15. Hexagon A
    hexagon Calculate area of regular hexagon inscribed in circle with radius r=9 cm.
  16. Bicycle wheel
    bicycle Bicycle wheel has a diameter of 70 cm. Approximately how many times the wheel rotates at 4.7 km long trip?
  17. Garden
    garden_2 Father dig up the garden in 9 hours. Son in 13 hours. How many hours take dig up the garden together?
  18. Similarity coefficient
    eqlateral_triangles The ratio of similarity of two equilateral triangles is 3.5 (ie 7:2). The length of the side of smaller triangle is 2.4 cm. Calculate the perimeter and area of ​​the larger triangle.
  19. Balls
    steel_ball Three metal balls with volumes V1=71 cm3 V2=78 cm3 and V3=64 cm3 melted into one ball. Determine it's surface area.
  20. Road
    cesta Between cities A and B is route 7 km long of fall average 4‰. Calculate the height difference of cities A and B.

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