Examples for 9th grade - page 12

  1. Octahedron - sum
    8sten On each wall of a regular octahedron is written one of the numbers 1, 2, 3, 4, 5, 6, 7 and 8, wherein on different sides are different numbers. For each wall John make the sum of the numbers written of three adjacent walls. Thus got eight sums, which also.
  2. Climb
    scenic_road Road has climbing 1:23. How big is a angle corresponds to this climbing?
  3. n-gon
    ngon_1 Gabo draw n-gon, which angles are consecutive members of an arithmetic sequence. The smallest angle is 70° biggest 170°. How many sides have Gabo's n-gon?
  4. OK circle
    circles2 Calculate the radius (circumradius) of the circle described right triangle with hypotenuse long 43 and one cathetus long 21.
  5. Motion
    bus_1 From two different locations distant 104 km started against car and bus. The car started at 5:30 with average speed 58 km/h. Bus started at 6:40 with average speed 79 km/h. When they meet? How many kilometers went the bus?
  6. Pyramid a+h
    jehlan_1 Calculate the volume and surface area of the pyramid on the edge and height a = 26 cm. h = 3 dm.
  7. Rotary cone
    cone_2 Rotary cone whose height is equal to the circumference of the base, has a volume 4772 cm3. Calculate the radius of the base circle and height of the cone.
  8. Rectangles
    rectangles How many rectangles with area 2832 cm2 whose sides is natural numbers are?
  9. Two doctors
    dr_cvach Doctor A will determine the correct diagnosis with a probability 80% and doctor B with a probability 72%. Calculate probability of correct diagnosis if patient is diagnosed by both doctors.
  10. 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.
  11. Cut and cone
    kuzel Calculate the volume of the rotation cone which lateral surface is circle arc with radius 14 cm and central angle 114 degrees.
  12. 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.
  13. Sale
    sale_percent If the product twice price cut by 20%, what percentage was price cut in total?
  14. Jewel
    rhombus3 Rhombus-shaped jewel have area of 86 mm2 and the edge in long 10 mm. Calculate the size of rhombus acute angle.
  15. 4s pyramid
    pyramid_regular Regular tetrahedral pyramid has a base edge a=6 and collaterally edge length b=15. What is its height?
  16. Circle and angle
    arc What is the length of the arc of a circle with radius r = 138 cm with cental angle 2.07 rad?
  17. Accidents
    nehoda-pomnik The count of accidents in 1993 caused 8009 women which is 7.1%. How many men caused the accidents?
  18. Trapezoid
    rectangular_trapezoid Are diagonals in a rectangular trapezoid perpendicular and bisect the angles?
  19. Tetrahedral pyramid
    krychle_3_jehlany Calculate the volume and surface of the regular tetrahedral pyramid if content area of the base is 20 cm2 and deviation angle of the side edges from the plane of the base is 60 degrees.
  20. RT - hypotenuse and altitude
    pravy_trojuholnik Right triangle TWS has hypotenuse s=202 km and altitude to s is 99 km. How long are hypotenuse segments?

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