Examples for 8th grade - page 49
- Hexagon 5
The distance of parallel sides of regular hexagonal is 81 cm. Calculate the length of the radius of the circle described to this hexagon.
Solve the inequation: 5k - (7k - 1)≤ 2/5 . (5-k)-2
Flowerbed has the shape of an isosceles obtuse triangle. Arm has a size 6.1 meters and an angle opposite to the base size is 93°. What is the distance from the base to opposite vertex?
The perimeter of a circular sector with an angle 2 rad is 53 cm. Determine the radius of the circle from which the sector comes.
The shooter fired to a target from distance 9 m The individual concentric circle of targets have a radius increments 1 cm (25 points) by 1 point. Shot was shifted by 16'(angle degree minutes). How many points should win his shot?
- Against each other
From two points A, B distant 45 km at the same time started two cars against each other at speeds 81 km/h and 67 km/h. How long does cars meet and what distance passes each of them?
- Map - climb
On the map of High Tatras in scale 1:25000 are cable car stations in the Tatranska Lomnica and in the Skalnate Pleso with distance 156 mm. Altitude of this stations are 944 m and 1755 m. What is average angle of climb of this cable car track?
What is the slope of the perpendicular bisector of line segment AB if A[-9,-8] and B[-8,0]?
- Wire D
Wire length 5 m is bent so that it forms a semicircle circuit (including the diameter). Determine the radius of the semicircle.
- Right isosceles
Calculate area of the isosceles right triangle which perimeter is 35 cm.
The rectangle shaped field with dimensions 979 m and 540 m harvested last year was 2775 q wheat. (1 q = 1 quintal = 100 kg). During the year, it was necessary to fix the pipe and therefore did kick wide 6 m parallel to the side of the field 540 m, where no
Calculate heights of the triangle ABC if sides of the triangle are a=48, b=81 and c=98.
Peter demolish box hole in the wall for window frame 48×48 cm. When they came masters fitted frame and window will be found that glass is 13.7 cm from the hole in each direction. Calculate how much percent less light enters the window than hole?
- Slope of track
Calculate the average slope of the rail tracks between Prievidza (309 m AMSL) and Bratislava (152 m AMSL), if the track is 158 km long.
- Engineer Kažimír
The difference between politicians-demagogues and reasonable person with at least primary education beautifully illustrated by the TV show example. "Engineer" Kažimír says that during their tenure there was a large decline in the price of natural gas, pri
- Linear system
Solve this linear system (two linear equations with two unknowns): x+y =36 19x+22y=720
Determine the percentage rate of keeper interventions if from 32 shots doesn't caught four shots.
Two boys started from one place. First went north at velocity 3 m/s and the second to the east with velocity 4 m/s. How far apart they are after minute?
- Eight palm
There grows 8 palms by the sea. At the first sitting one parrot, on second two, on third sits four parrots on each other twice the previous parrots sitting on a previous palm. How many parrots sitting on eighth palm?
Three schools are attended by 678 pupils. To the first attend 21 students more and to the third 108 fewer students than to second school. How many students attend the schools?