# Examples for 8th grade - page 26

1. Trapezoid RT The plot has a shape of a rectangular trapezium ABCD, where ABIICD with a right angle at the vertex B. side AB has a length 36 m. The lengths of the sides AB and BC are in the ratio 12:7. Lengths of the sides AB and CD are a ratio 3:2. Calculate consumptio
2. Rectangular trapezoid The rectangular trapezoid ABCD is: /AB/ = /BC/ = /AC/. The length of the median is 6 cm. Calculate the circumference and area of a trapezoid.
3. Earth's diameter The Earth's diameter on the equator is approximately 12750 km. How long does the Gripen flyover the Earth above the equator at 10 km if it is at an average speed of 1500 km / h?
4. Circumscription Calculate radius of the Circumscribed circle in the rectangle with sides 20 and 19. It can be rectangle inscribed by circle?
5. Components In the box are 8 white, 4 blue and 2 red components. What is the probability that we pull one white, one blue and one red component without returning?
6. Metal alloy What is the ratio of metals in the alloy that is in the 50 tonnes of steel to 30 kg nickel?
7. Cuboid The volume of the cuboid is 245 cm3. Each cuboid edge length can be expressed by a integer greater than 1 cm. What is the surface area of the cuboid?
8. Three digits number How many are three-digit integers such that in they no digit repeats?
9. Trapezoid ABCD v2 Trapezoid ABCD has length of bases in ratio 3:10. The area of riangle ACD is 825 dm2. What is the area of trapezoid ABCD?
10. Subway Subway train went between two stations that gradually accelerated for 26 seconds and reached a speed of 72 km/h. At this rate, went 56 seconds. Then 16 seconds slowed to a stop. What was the distance between the stations?
11. Car inflation About what percentage price of car increased if price rose from €1880 to €2200?
12. Temperature calculus Calculate percentage of temperature increase if changed from -9°C to 22°C? Solve pure quadratic equation ?.
14. Motor physics Car traveling at 130 km/h on the highway. Pulling power of the motor is 8 kN. Determine engine power in kW.
15. Hurry - rush At an average speed 7 km/h I will come from the school to the bus stop for 30 minutes. How fast I need to go if I need to get to the bus stop in 21 minutes?
16. Diamond Determine the side of diamond if its content is S = 353 cm2 and one diagonal u2 = 45 cm.
17. Liters in cylinder Determine the height at which level 24 liters of water in a cylindrical container having a bottom diameter 36 cm.
18. Complete construction Construct triangle ABC if hypotenuse c = 7 cm and angle ABC = 30 degrees. / Use Thales' theorem - circle /. Measure and write down the length of legs.
19. Triangle Calculate the sides of the triangle if its area S = 630 and the second cathethus is shorter by 17.
20. Diameter If the endpoints of a diameter of a circle are A(10, -1) and B (3, 10), what is the radius of the circle?

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