Examples for 8th grade - page 45

  1. Two circles
    two_circles Two circles with a radius 4 cm and 3 cm have a center distance 0.5cm. How many common points have these circles?
  2. Circle sector
    vysec Circular sector with a central angle 10 ° has area 254 cm2. Calculate its radius r.
  3. Earth's surface
    earth_globe The greater part of the earth's surface (r = 6371 km) is covered by oceans; their area is approximately 71% of the Earth's surface. What is the approximate area of the land?
  4. Tiler
    asdasd On what surface m2 tiler must lay 30 square tiles, each of which has a side 25 cm?
  5. Triangle angles
    triangle_4 In a triangle ABC the interior angle at the vertex C is twice as the internal angle at the point A. Outer angle at the point B measured 117 degrees. How big is the outer angle at the vertex A?
  6. Greenhouse
    foliovnik Garden plastic greenhouse is shaped half cylinder with a diameter of 6 m and base length 20 m. At least how many m2 of plastic is need to its cover?
  7. Isosceles trapezoid
    rr_licho The lengths of the bases of the isosceles trapezoid are in the ratio 5:3, the arms have a length of 5 cm and height = 4.8 cm. Calculate the circumference and area of a trapezoid.
  8. Seamstress
    krajcirka Seamstress bought two kinds of textile together 25 meters. One at 50 SKK and the second 70 SKK per meter. How many meter bought from this two textiles when paid totally 1540 SKK?
  9. Median
    medians.JPG In triangle ABC is given side a=10 cm and median ta= 13 cm and angle gamma 90°. Calculate length of the median tb.
  10. Pair
    dvaja They have together 48 years - he has 2 times as she was when he was equal as she has today ....
  11. Obtuse angle
    10979326_654459541349455_1236723697_n The line OH is the height of the triangle DOM, line MN is the bisector of angle DMO. obtuse angle between the lines MN and OH is four times larger than the angle DMN. What size is the angle DMO? (see attached image)
  12. QuizQ2
    debil_z_tv The square of the first number is equal to three-fifths of the second number. Determine both numbers if you know that the second number is 5 times greater than the first, and neither of numbers is not equal to zero.
  13. Snowman
    snehuliak_1 In a circle with a diameter 41 cm are drawn 3 circles /as a snowman/ where: its diameters are integers, each larger circle diameter is 3 cm larger than the diameter of the previous circle. Determine snowman height if we wish highest snowman.
  14. Motor physics
    car_motor Car traveling at 97 km/h on the highway. Pulling power of the motor is 6 kN. Determine engine power in kW.
  15. Rhombus
    rhombus_4 Calculate the length of the diagonal AC of the rhombus ABCD, if its perimeter is 352 dm and the other diagonal BD has length 148 dm.
  16. Unions
    odbory_prdel Calculate how much money per year would go to the treasury of unions if 447 thousand employee join unions with an average net salary of 539 euros and if memberhip in union cost 1% of the net monthly salary.
  17. Base
    rotunda Base of building is circle with diameter 39 m. Calculate the circumference of a circular trench witch diameter is 21 cm wider than the diameter of the base.
  18. Cu wire
    medeny-drat Copper wire has a length l = 210 m and diameter d = 10 mm. Calculate the weight if density of copper is ρ = 8500 kg/m3. Result round to one decimal place.
  19. Square Number
    squared-number If to a square of integer number add 49, we get the square of next integer number. What is the original number?
  20. Mean
    integrales if the mean of the set of data 10, 13, 8, 18, 20, 17, 19, 3, 10, 8, 8, 3, 12, 15, 14, 4, 20, 19, x is 24.36, what is the value of x?

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