# Examples for 8th grade - page 13

- Road embankment

Road embankment has a cross section shape of an isosceles trapezoid with bases 5 m and 7 m, and 2 m long leg. How many cubic meters of soil is in embankment length of 1474 meters? - Percent calculation

Calculate 61% if 85% is 38. - OK circle

Calculate the radius (circumradius) of the circle described right triangle with hypotenuse long 33 and one cathetus long 17. - Estate

Semicircle estate must be fence. The straight section has 26 meters long fence. How many meters of fence should buy? - Prism

Calculate the volume of the rhombic prism. Base of prism is rhombus whose one diagonal is 47 cm and the edge of the base is 28 cm. The edge length of the base of the prism and height is 3:5. - Pyramid a+h

Calculate the volume and surface area of the pyramid on the edge and height a = 26 cm. h = 3 dm. - Canopy

Mr Peter has metal roof cone shape with a height of 101 cm and radius 189 cm over well. He needs paint the roof with anticorrosion. How many kg of color must he buy if the manufacturer specifies the consumption of 1 kg to 4.3 m^{2}? - Two doctors

Doctor A will determine the correct diagnosis with a probability 86% and doctor B with a probability 87%. Calculate probability of correct diagnosis if patient is diagnosed by both doctors. - Stairway

What angle rising stairway if step height in 17 cm and width 27 cm? - Square 2

Points D[10,-8] and B[4,5] are opposed vertices of the square ABCD. Calculate area of the square ABCD. - Plan of the village

Plan of the municipality in 1:1000 scale has plotted garden with dimensions 25 mm and 28 mm. Determine the area of gardens in ares in reality. - n-gon

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? - Climb

Road has climbing 1:27. How big is a angle corresponds to this climbing? - Parallelogram

Calculate area of the parallelogram ABCD as shown if |AB| = 19 cm, |BC| = 18 cm and angle BAD = 90° - Rectangles

How many rectangles with area 3002 cm^{2}whose sides is natural numbers are? - Motion

From two different locations distant 232 km started against car and bus. The car started at 5:20 with average speed 64 km/h. Bus started at 7:30 with average speed 80 km/h. When they meet? How many kilometers went the bus? - Rotary cone

Rotary cone whose height is equal to the circumference of the base, has a volume 229 cm^{3.}Calculate the radius of the base circle and height of the cone. - Unknown x

If we add to unknown number 21, then divide by 6 and then subtract 51, we get back an unknown number. What is this unknown number? - Sale

If the product twice price cut by 25%, what percentage was price cut in total? - Circle section

Equilateral triangle with side 34 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.

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