







The code on a new phone 
20180202 

Maria pose la question : Hi 
My husband gave me a new Samsung Galaxy mobile for out anniversaire gift. He set me a challenge which I have to solve before I can use the Phone. He has set the pin code with numbers 4, 7 and 0 and created a four digit code with the said numbers. Is there a way I can somehow list all possible combinations and try them all? Thanks! Penny Nom lui répond. 





A pool with a dome 
20170911 

Bruce pose la question : A round 24 foot pool. A dome 3 feet above pool in center. How many feet across is the dome touching top rail straight across of pool? Penny Nom lui répond. 





A lock with 3 tumblers 
20170729 

Carol pose la question : I have a lock that has 3 tumblers. The numbers are 0  9. I cannot recall what I set the combination to. How many combinations will there be with three numbers? Penny Nom lui répond. 





The area of a domed roof 
20151113 

Brandon pose la question : I have a tank with a 13' radius that has a domed roof of 3.5' tall How do I figure out the area in SQFT? Penny Nom lui répond. 





The surface area of a circular dome 
20140410 

Shafiqah pose la question : Is this a dome's surface area formula??
{{2 × π r × h square units}}
Is the surface area of the floor for the dome is calculate too in this formula?
Thanks for answering. =) Robert Dawson and Penny Nom lui répond. 





The surface area of a dome 
20120606 

sravya pose la question : how to calculate surface area of a dome if its base radius and height are known and neither it is hemisphere nor radius of sphere is known?? Walter Whiteley lui répond. 





Two great circles 
20111006 

Jean pose la question : "Two great circles lying in planes that are perpendicular to each
other are drawn on a wooden sphere of radius "a". Part of the sphere
is then shaved off in such a way that each cross section of the
remaining solid that is perpendicular to the common diameter of the
two great circles is a square whose vertices lie on these circles.
Find the volume of this solid."
I don't understand the geometry of the problem.
Can you please explain the problem and if possible draw a diagram for me
? Chris Fisher lui répond. 





Painting a hemispheric dome 
20100509 

Jone pose la question : If a hemispheric dome has a height of 20m and it take 5 gallons of paint
to paint the floor, how many gallons of pain are needed to paint the
inside of the dome? Penny Nom lui répond. 





Surface area of a dome 
20090916 

Charlie pose la question : Why is the calculation for the surface area of a domed tank less than the surface area of a flat top tank.
Using domed tank formula 2*pi*r(r(rdome ht) works out to be less surface area than a flat top tank area formula pi*r x r,
Shouldn't the dome have more surface area than the flat surface ? Harley Weston lui répond. 





A spherical dome 
20090803 

Eric pose la question : I have recently been asked to resurface a dome sculpture for my local council but i'm having problems working out the area. Here are the dimensions.
The height of the dome is 3m from the ground to the top of the arc. The arc itself from the ground rising up to the 3m point and back down, is 10m. The dome is 7m wide from one side to the other through the centre, at ground level.
I hope there is enough detail here. It's been a long time since i was in a maths class.
Thank you, hope to here from you soon! Stephen La Rocque lui répond. 





Two circles on a dome 
20090701 

Beth pose la question : My question is related to a dome I would like to construct, for which I know the circumference of the base: 120ft.
I now need to figure out the diameters of two smaller circles, one at 20ft along the arc of the dome form the ground,
and the other at 30ft along the arc.
Assuming a true hemisphere, or 180 degrees total arc, how can I calculate these two circumferences?
Beth Stephen La Rocque lui répond. 





The surface area of a tank 
20090625 

Charles pose la question : I need to calculate the external wall and top sqft surface area of a tank 54ft od x 15ft high with a dome top 54ft od x 8ft high. Penny Nom lui répond. 





Exterior square footage of a dome 
20080819 

Richard pose la question : I have to gold leaf a dome with a circumference of 29'. What would the exterior square footage be? Penny Nom lui répond. 





The surface area of a dome 
20070211 

chris pose la question : I need to figure the surface area of a dome which is 96" across and 48" tall. Could you help please? Thanks! Penny Nom and Melanie Tyrer lui répond. 





A dome with a square base 
20061017 

Danielle pose la question : I need to know how to calculate the area of a dome that has a square base. In order to insulate the room I need to find the area of it but I am not sure how to do so because there is no formula for domes with square bases. Basically, the floor has 4 corners but the ceiling is dome shaped starting directly from the floor. Stephen La Rocque and Penny Nom lui répond. 





The Mitchell Park Domes 
20060401 

Nicole pose la question : I would like to know how I could find the volume underneath the Mitchell Park Domes? The Diameter of the Domes is 140ft, 85ft high and 15,000 square feet. Stephen La Rocque lui répond. 

