CPhill

Eh...you're right..I read "diameter" as "radius'.....let me go back and correct that....sorry!!!

Sorry, Mathematician....I'm kinda' 'stuck" with using Trig.....if I think of some geometric way to do it...I'll let you know...!!!

Here's the only problem with this, Melody......

Let's first find out how long it takes to travel 400 ft....this is given by

400 = (118.25)cos(35)t  

t = about 4.13 sec

Let y = 0 be the original height....then we would be looking for how many inches it would clear a 7 ft wall

So we have

y = -16(4.13)^2 + 118.25sin(35)(4.13) = 7.2 ft....and this is the heightt in ft at 4.13 sec

So...it clears the all by about .2 ft = 2.4 inches

Here you go.....

The Law of Cosines is this

c^2  = a^2 + b^2 - 2(a)(b)cos(theta)

Where c is the opposite side to the angle "theta" ....and "theta" is the included angle between sides a and b.

So...... in the circle, a and b are radii = 9  ....and since there are three equal sides of the triangle, each side spans an arc of 120 degrees.

We can use the Law of Cosines to solve this..letting x be the side length, we have...

x^2 =  (4.5)^2 + (4.5)^2 - 2(4.5)(4.5)cos120

x= √60.75  = 7.7942286340599478  = 4.5√3

Thanks, Mathematician...for seeing my previous error...!!!

The common ratio is 25/9  

No "perfect" number divides this "perfectly"...(since all perfect numbers found so far are even, and no even divides an odd)

The largest perfect number that will divide it resulting in a "mixed" number is 8128

Use the tangent inverse....

So we have

tan^-1 (18/13) = about 54.16°   ( ± n180° )