Examples for 8th grade - page 56

  1. Circle section
    circle_segment Equilateral triangle with side 50 is inscribed circle section whose center is in one of the vertices of the triangle and the arc touches the opposite side. Calculate: a) the length of the arc b) the ratio betewwn the circumference to the circle sector.
  2. 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?
  3. Icerink
    klzisko-korcule Rectangular rink with dimensions of 79.5 m and 529 dm must be covered with a layer of ice 4.5 cm thick. How many liters of water is necessary for the formation of ice when the volume of ice is 10.9% greater than the volume of water.
  4. n-gon II
    x-gon_1 What is the side length of the regular 9-gon circumscribed circle of radius 13 cm?
  5. Block
    brick_lego Calculate the volume of a cuboid ABCDEFGH if |AB| = 11 cm, |BC| = 8 cm and the angle ∠CDG = 29.4°
  6. Addends
    1plus1 Number 389 divide into the two addends that the first was 6 greater than 60% of the second. Determine these addends.
  7. Prism
    3b_hranol Right angle prism, whose base is right triangle with leg a = 3 cm and hypotenuse c = 5 cm has same volume as a cube with an edge length of 1 dm. a) Determine the height of the prism b) Calculate the surface of the prism c) What percentage of the cube'
  8. Sines
    sines In ▵ ABC, if sin(α)=0.5 and sin(β)=0.1 calculate sin(γ)
  9. Steamship
    parnik Between the two ports on the river is going steamship. The journey there and back takes 14:49. Downstream steamship traveling at 21 km/h, upstream 9 km/h. What is the distance between the ports?
  10. Triangle ABC
    triangles_3 Calculate the sides of triangle ABC with area 1789 cm2 and if a: b: c = 6:16:11
  11. Truck
    truck Truck went for 5 hours and 21 minutes. If truck increase speed by 19 km/h, went same distance in 2.9 hours. Calculate this distance.
  12. 2x cone
    truncated_cone_2 Circular cone height 60 cm was cut plane parallel with base. Volume of these two small cones is the same. Calculate the height of the smaller cone.
  13. Cubes
    two_cubes Surfaces of cubes, one of which has an edge of 18 cm shorter than the other, differ by 7776 mm2. Determine the length of the edges of this cubes.
  14. Box
    uhlopriecka Calculate the angle between box base 5 x 7 and body diagonal length 14.
  15. Concrete pipe
    concrete_pipe Concrete pipe is cylindrical with an inner diameter 130 cm and outer 142 cm. Calculate the surface of the concrete pipe, if it is 6 m long.
  16. Magnification of the square
    square If we increase the square side, increase the content of the 42 %. About what percentage was increased his sides?
  17. Similarity n-gon
    podobnost 11-gones ABCDEFGHIJK and A'B'C'D'E'F'G'H'I'J'K' are similar. The area of 11-gon ABCDEFGHIJK is S1=254 cm2 and the diagonal length HG is 20 cm. Calculate area of the 11-gon A'B'C'D'E'F'G'H'I'J'K' if H'G' = 36 cm.
  18. Rotation of the Earth
    earth_1 Calculate the circumferential speed of the Earth's surface at a latitude of 53.7°​​. Consider a globe with a radius of 6378 km.
  19. Apples 2
    jablka_6 Dried apples contain 15% water. Fresh apples contain 80% water. How many kg of apples we need buy in order to get 3 kg of dried apples?
  20. Frameworks is bad
    space Calculate how many percent will increase the length of an HTML document, if any ASCII character unnecessarily encoded as hexadecimal HTML entity composed of six characters (ampersand, grid #, x, two hex digits and the semicolon). Ie. space as:  

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