# Perimeter - 7th grade (12y) - math problems

#### Number of problems found: 159

• Tractor wheels The front wheel of the tractor has a circumference of 18 dm and the rear 60 dm. We will make a red mark on the lowest point of both wheels. The tractor then starts. At what distance from the start will both marks appear identically at the bottom again?
• Gardens The area of the square garden is 3/4 of the area of the triangular garden with sides of 80 m, 50 m, 50 m. How many meters of the fence do we need to fence a square garden?
• Gears The front gear on the bike has 32 teeth and the rear, on the wheel, has 12 teeth. How many times does the rear wheel of the bike turns if you turn the right pedal 30 times? What distance will you go if the circumference of the bicycle wheel is 250 cm?
• Similar triangles Triangle A'B'C 'is similar to triangle ABC, whose sides are 5 cm, 8 cm, and 7 cm long. What is the length of the sides of the triangle A'B'C ' if its circumference is 80 cm? Calculate the surface of a quadrilateral prism according to the input: Area of the diamond base S1 = 2.8 m2, length of the base edge a = 14 dm, height of the prism 1,500 mm.
• Second side Calculate the length of the other side of the rectangle if its circumference is 60 cm and one side is 10 cm long.
• The hollow cylinder The hollow cylinder has a height of 70 cm, an outer diameter of 180 cm and an inner diameter of 120 cm. What is the surface of the body, including the area inside the cavity?
• Winch drum Originally an empty winch drum with a diameter of 20 cm and a width of 30 cm on the rescue car, he started winding a rope with a thickness of 1 cm beautifully from edge to edge. The winch stopped after 80 turns. It remains to spin 3.54m of rope (without h
• Square sides If we enlarge the side of the square by a third, its circumference will be 20 cm larger than the original. What is the side of the square?
• Sum of the edges The sum of the lengths of all edges of the cube is 72 cm. How many cm2 of colored paper are we going to use for sticking?
• Cross five The figure on the picture is composed of the same squares and has a content of 45cm². What's its perimeter?
• Plot The land is in the shape of a square with a dimension of 22 meters. How much will we pay for the fence around the entire plot?
• Perimeter of the circle Calculate the perimeter of the circle in dm, whose radius equals the side of the square containing 0.49 dm2?
• Tablecloths The restaurant has sixty-two square tablecloths with a side length of 150 cm and 36 rectangular tablecloths with dimensions of 140 cm and 160 cm. A) How many meters of hemming ribbon will be needed if we add 50 cm to each tablecloth? B) The ribbon sale in
• Rectangles Vladimir likes to draw rectangles. Yesterday he created all rectangles that had sides in centimeters and a circumference of 18 cm. How many rectangles of different dimensions have been drawn?
• Coal mine The towing wheel has a diameter of 1.7 meters. How many meters does the elevator cage lower when the wheel turns 32 times? Calculate the radius of the circle whose length is 107 cm larger than its diameter
• The perimeter 3 The perimeter of a rectangle is 35 cm. The ratio of the length to its width is 3:2. Calculate the dimensions of the rectangle
• Triangular prism Calculate a triangular prism if it has a rectangular triangle base with a = 4cm and hypotenuse c = 50mm and height of the prism is 0.12 dm.
• Velocipedes In the 19th century, bicycles did not have a chain drive, and the pedals were connected directly to the wheel axis. This wheel diameter gradually increased until the so-called high bicycles (velocipedes) with a front wheel diameter of up to 1.5 meters, wh

Do you have an interesting mathematical word problem that you can't solve it? Submit a math problem, and we can try to solve it.

We will send a solution to your e-mail address. Solved examples are also published here. Please enter the e-mail correctly and check whether you don't have a full mailbox.

Please do not submit problems from current active competitions such as Mathematical Olympiad, correspondence seminars etc...