Nope you have an ellipse...
The radius for the 9'6 points is 6'8 5/8 which leaves you 23 5/8" at the center of the arc.
A sq + B sq = C sq the hypontenus theory.
4'9 being A & B leaving 6'8 5/8 for C
6'8 5/8 minus 4'9 at the center leaves 23 5/8" not 17" I think anyway... I could be wrong?
Try putting 2 nails 9'6 apart and let a string droop down to 17" that may be your best way to get your answer.
By the way the tramel Mark speaks of can be made with a 1x4 with a nail for the compass point and another nail to mark out the arc. I do that for arc top windows & even laying out high rise entrance circles... works great for the trim to put two nail on the making end. Gives you both diameters.
Alter Eagle Construction & Design
- 15 Old House Features We Shouldn't Abandon
- 17 Tiny Bathrooms We Love
- 30 Things Everyone Should Know
- 21 Expert Choices for Fail-Safe Paint Colors
- 20 Easy 60-Minute Home Improvements
- 10 IKEA Favorites Made New with Paint
- The Tiniest Appliances You Never Knew Existed
- 133 Smart Storage Ideas for the Whole House
- 16 New Ways to Store Kitchen Necessities
- 8 Ways to Make a Small Room Look Big
- Sweet Dreams: 15 Inventive Beds You Can Make Yourself
- 10 Fall Door DIYs for the Best House on the Block
- The Cheapest Ways to Boost Home Value
- 10 New Uses for Old Doors
- 26 Easy Painted Pumpkins for Halloween
- 15 Once-Popular Home Items Now Vanishing
- 8 Unique Ways to Build Your Own Table
- Woodworking for Beginners: 10 Projects
- 7 Reasons to Reconsider Wallpaper
- 10 New Uses for Old Dressers
- 7 Upgrades You Can Do in Under 300 Seconds
- 10 Thrifty DIY Ways to Organize Your Home
- 12 "Different" Ways to Store Firewood
- 5 DIY Farm Table Projects That Will Last a Lifetime
- Beyond White: 11 Bathroom Paint Colors
- 10 DIYs for a Festive Front Door This Fall
- 10 Creative New Ways to Use Old Bottles
- The 10 Best Things to Buy Secondhand
- 16 Must-See Coffee Tables You Can DIY—Easily!