# Examples for 8th grade - page 29

- Cuboid 5

Calculate the weight of the cuboid with dimensions of 12 cm; 0.8 dm and 100 mm made from spruce wood (ς = 550 kg/m^{3}). - Strawberries

Father collects strawberries himself in 4 hours, son in 10 hours. How long will it take them along when dad comes to help son collect strawberries after 4 hours? - Crown

Siblings collect a 2-crowns and 5-crowns. Together have 80 coins with a total of value 310 crowns. How many saved two-crowns and how many five-crowns? - Father and son

Father is three times older than his son. 12 years ago father was nine times older than the son. How old are father and son? - Painter 3

Dad want to paint wall high 250 cm wide and 230 cm with wallpaper. How many meters must buy wallpaper if wallpaper width is 60 cm? - Chicken

I threw three chicken for a handful of grains and I noticed that it eat in a ratio of 8:7:6 and two of them grabbed 156 grains. How many grains have fought that chicken? - SAS triangle

The triangle has two sides long 7 and 19 and included angle 144°11'59″. Calculate area of this triangle. - 30-60-90

The longer leg of a 30°-60°-90° triangle measures 7. What is the length of the shorter leg? - RT and ratio

Right triangle whose cathetus are in a ratio 6:17 has hypotenuse 47 m long. How long are cathetus? - Revenue

Mr. Robert and Mr. Norbert get together € 1400. The revenue split in the ratio of 4:3, depending upon each work. How many got each of them? - Trapezoid

Area of trapezoid is 135 cm^{2.}Sides a, c and height h are in a ratio 6:4:3. How long are a,c and h? Make calculation... - Water

On the lawn which has area 243 m^{2}rained 5 mm of water. How many liters of water rained? - Quadrangular prism

The quadrangular prism has a volume 648 cm^{3.}Trapezoid which is its base has the dimensions bases: a = 10 cm, c = 5 and height v = 6 cm. What is the height of the prism? - Flowerbed 2

Around the square flower bed in a park is sidewalk 1.4 m wide. The area of this sidewalk is 125 m^{2.}What is the area of the flowerbed? - Circle sector

Circular sector with a central angle 10 ° has area 254 cm^{2.}Calculate its radius r. - 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. - Pyramid

Cuboid ABCDEFGH has dimensions AB 3 cm, BC 4 cm, CG 5 cm. Calculate the volume and surface area of a triangular pyramid ADEC. - Field with vegetables

Field planted with vegetables has shape of a rectangular isosceles triangle with leg length of 24 m. At the vertices of the triangle are positioned rotating sprinklers with a range of 12 m. How much of the field sprinkler doesn't irrigated? - Number

Is number 4.764023 irrational? - Trapezoid ABCD

Calculate the perimeter of trapezoid ABCD if we know the side c=25, b=16 which is also a height and side d=27.

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