Nonagon

Calculate the area and perimeter of a regular nonagon if its radius of the inscribed circle is r = 10cm

Correct result:

S =  327.5732 cm2
o =  65.5146 cm

Solution:

r=10 cm n=9  A=360/n=360/9=40  tanA/2=a/2r  a=2 r tan(A/2)=2 10 tan(40/2)7.2794 cm  S1=r a2=10 7.2794236.397 cm2 S=n S1=9 36.397=327.5732 cm2
o=n a=9 7.2794=65.5146 cm



We would be pleased if you find an error in the word problem, spelling mistakes, or inaccuracies and send it to us. Thank you!






Showing 2 comments:
#
Math student
I need to draw a nonagon for my daughter and she has to have each at 4cm

#
Matematik
try to start with angle 360/9 = 40°... Draw nine isosceles triangles with base a=4 cm and opposite angle 40°.
Or if you may calculate diameter of described circle - draw a circle and divide it into nine equal segments. (divide by 40° angle)

avatar









Tips to related online calculators
Pythagorean theorem is the base for the right triangle calculator.
See also our trigonometric triangle calculator.

 
We encourage you to watch this tutorial video on this math problem: video1   video2

Next similar math problems:

  • Pentagon
    5gon Calculate the length of side, circumference and area of a regular pentagon, which is inscribed in a circle with radius r = 6 cm.
  • Regular n-gon
    regular_polygons Which regular polygon have a radius of circumscribed circle r = 10 cm and the radius of inscribed circle p = 9.962 cm?
  • 30-gon
    30gon At a regular 30-gon the radius of the inscribed circle is 15cm. Find the "a" side size, circle radius "R", circumference, and content area.
  • Pentadecagon
    220px-Regular_polygon_15_annotated.svg Calculate the content of a regular 15-sides polygon inscribed in a circle with radius r = 4. Express the result to two decimal places.
  • Glass
    pohgar How many glass are needed to produce glass with base regular 5-gon if one base triangle in the base is 4.2 square cm and the height is 10 cm?
  • Circle sector
    vysec Circular sector with a central angle 160° has area 452 cm2. Calculate its radius r.
  • 4side pyramid
    ihlany Calculate the volume and surface of 4 sides regular pyramid whose base edge is 4 cm long. The angle from the plane of the sidewall and base plane is 60 degrees.
  • Octagonal pyramid
    octagonl_pyramid2 Find the volume of a regular octagonal pyramid with height v = 100 and the angle of the side edge with the plane of the base is α = 60°.
  • Regular quadrangular pyramid
    6 How many square meters are needed to cover the tower the shape of a regular quadrangular pyramid base edge 10 meters, if the deviation lateral edges from the base plane are 68 °? Calculate coverage of waste by 10%.
  • Perimeter of triangle
    rt_triangle_1 In triangle ABC angle A is 60° angle B is 90° side size c is 15 cm. Calculate the triangle circumference.
  • Pyramid 8
    ihlan 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°.
  • Four circles
    circles_2 1) Calculate the circle radius if its area is 400 cm square 2) Calculate the radius of the circle whose circumference is 400 cm. 3) Calculate circle circumference if its area is 400 cm square 4) Calculate the circle's area if perimeter 400 cm.
  • Right triangle trigonometrics
    triangle2 Calculate the size of the remaining sides and angles of a right triangle ABC if it is given: b = 10 cm; c = 20 cm; angle alpha = 60° and the angle beta = 30° (use the Pythagorean theorem and functions sine, cosine, tangent, cotangent)
  • Nine-gon
    9gon_1 Calculate the perimeter of a regular nonagon (9-gon) inscribed in a circle with a radius 13 cm.
  • Tetrahedral pyramid
    ihlan Determine the surface of a regular tetrahedral pyramid when its volume is V = 120 and the angle of the sidewall with the base plane is α = 42° 30´.
  • Right triangle
    right_triangles Calculate the missing side b and interior angles, perimeter, and area of ​​a right triangle if a=10 cm and hypotenuse c = 16 cm.
  • Inscribed circle
    inscribed_circle XYZ is right triangle with right angle at the vertex X that has inscribed circle with a radius 5 cm. Determine area of the triangle XYZ if XZ = 14 cm.