Examples for 8th grade - page 74
- Cylinder surface area
Volume of a cylinder whose height is equal to the radius of the base is 678.5 dm3. Calculate its surface area.
- Hexagonal pyramid
Calculate the volume and the surface of a regular hexagonal pyramid with a base edge length 3 cm and a height 5 cm.
Base of perpendicular triangular prism is a right triangle with cathetuses 4.5 cm and 6 cm. What is the surface of the prism, if its volume of 54 cubic centimeters.
- Truncated cone
A truncated cone has a base radius 40 cm and 10 cm and a height of 25 cm. Calculate its surface area and volume.
- Ascent and descent
Car goes 114 km track, which consists of ascent and descent at time of 1 hour 35 minutes. When climbing moves at the speed 48 km/h and downhill 25 m/s. What is the length of climb and descent?
Find the volume and surface area of prism with base of an equilateral triangle with side 7 dm long and the body height of 1.5 m.
- Hexa prism
Determine the volume of hex prism with edge base 4 cm. The body height is 28 cm.
- 6 regular polygon
It is given 6 side regular polygon whose side is 5 cm. Calculate its content area. Compare how many more cm2 (square centimeters) has a circle in which is inscribed the 6-gon.
Four dwarfs would prepare firewood for Snow White in580 minutes. After an hour and a half they recruit friends so that finished preparing the wood for 280 minutes. How many dwarfs they recruited?
arc length = 17 cm area of sector = 55 cm2 arc angle = ? the radius of the sector = ?
- Chors centers
The circle with a diameter 17 cm, upper chord /CD/ = 10.2 cm and bottom chord /EF/ = 7.5 cm. The midpoints of the chords H, G is that /EH/ = 1/2 /EF/ and /CG/ = 1/2 /CD/. Determine the distance between the G and H, if CD II EF (parallel).
ABCD is a rhombus, ABD is an equilateral triangle and AC is equal to 4. Find the area of the rhombus.
Calculate how many liters of air will fit in the tent that has a shield in the shape of an isosceles right triangle with legs r = 3 m long the height = 1.5 m and a side length d = 5 m.
- Points on circle
In the Cartesian coordinate system with the origin O is a sketched circle k /O; r=2 cm/. Write all the points that lie on a circle k and whose coordinates are integers. Write all the points that lie on the circle I / O; r=5 cm / and whose coordinates are i
- Pyramid 8
Calculate the volume and the surface area of a regular quadrangular pyramid with the base side 9 cm and side wall with the base has an angle 75°.
- TV diagonal
Diagonal TV is 0.56 m long, how big the television sreen is if the aspect ratio is 16:9?
- Chord circle
The circle to the (S, r = 8 cm) are different points A, B connected segment /AB/ = 12 cm. AB mark the middle of S'. Calculate |SS'|. Make the sketch.
- Journey to school
On the way to school I went steady step. In the first half of the journey, I counted every second step, in the second half every third. How many steps I do when I went to school if I counted double step are 250 more than three steps?
a) Dusan break two same window, which has triangular shape with a length of 0.8 m and corresponding height 9.5 dm. Find how many dm2 of glass he needs to buy for glazing of these windows. b) Since the money to fix Dusan has not, must go to the paint job
Area of trapezoid is 135 cm2. Sides a, c and height h are in a ratio 6:4:3. How long are a,c and h? Make calculation...