Examples for 9th grade - page 16
If tg α = 3.8, Calculating sin α, cos α, cotg α .
- Truncated cone
Calculate the height of the rotating truncated cone with volume V = 1299 cm3 and a base radii r1 = 6.3 cm and r2 = 9.7 cm.
Calculate the volume of a cuboid ABCDEFGH if |AB| = 11 cm, |BC| = 8 cm and the angle ∠CDG = 29.4°
- Cone and the ratio
Rotational cone has a height 28 cm and the ratio of the base surface to lateral surface is 4: 7. Calculate a surface of the base and the lateral surface.
- Cardboard box
We want to make a cardboard box shaped quadrangular prism with rhombic base. Rhombus has a side of 5 cm and 8 cm one diagonal long. The height of the box to be 12 cm. The box will be open at the top. How many square centimeters cardboard we need, if we cal
- MO - triangles
On the AB and AC sides of the triangle ABC lies successive points E and F, on segment EF lie point D. The EF and BC lines are parallel and is true this ratio FD:DE = AE:EB = 2:1. The area of ABC triangle is 27 hectares and line segments EF, AD, and DB se
- Morse alphabet
Calculate how many words of Morse code to create compiling commas and dots in the words of one to five characters.
At the table sit 12 people, 6 on one side and 6 on the other side. Among them are 5 pairs. Every pair wants to sit opposite each other. How many ways can they sit?
- Sphere A2V
Surface of the sphere is 306 m2. What is its volume?
Between the two ports on the river is going steamship. The journey there and back takes 14:49. Downstream steamship traveling at 21 km/h, upstream 9 km/h. What is the distance between the ports?
Calculate length of the vector v⃗ = (-2.5, 6.25, -4.25).
Calculate how many 25 kg bags of leveling concrete must be purchased if we leveling room 28 m2 to the "height" 12 mm if consumtion is 1.7 kg per square meter and millimeter thickness.
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
- Three workers
Three workers A, B, C have to work on a specific task. Workers A and B completed whole task in 25 days, B together with C for 16 days, A together with C for 10 days. How long it would take to complete the task every one of them alone? How long it would.
- Two balls
Two balls, one 8cm in radius and the other 6cm in radius, are placed in a cylindrical plastic container 10cm in radius. Find the volume of water necessary to cover them.
Marie earns 1.8 liters of blueberries for 1.2 hours, Peter 2.6 liters for 1.2 hours. How long have earns together one liter?
- Heron backlaw
Calculate missing side in a triangle with sides 33 and 27 and area 118.3.
Conduit has a cross section 492 mm. Maybe put it into 5 conductors with a cross section S2 $mm2?
- Amazing number
An amazing number is name for such even number, the decomposition product of prime numbers has exactly three not necessarily different factors and the sum of all its divisors is equal to twice that number. Find all amazing numbers.
- Triangle angles
The angles α, β, γ in triangle ABC are in the ratio 10:5:6. Calculate size of angles.