Answer:
A
Step-by-step explanation:
30/.5 = 60
60 + 10 = 70
OK. I did it. Now let's see if I can go through it without
getting too complicated.
I think the key to the whole thing is this fact:
A radius drawn perpendicular to a chord bisects the chord.
That tells us several things:
-- OM bisects AB.
'M' is the midpoint of AB.
AM is half of AB.
-- ON bisects AC.
'N' is the midpoint of AC.
AN is half of AC.
-- Since AC is half of AB,
AN is half of AM.
a = b/2
Now look at the right triangle inside the rectangle.
'r' is the hypotenuse, so
a² + b² = r²
But a = b/2, so (b/2)² + b² = r²
(b/2)² = b²/4 b²/4 + b² = r²
Multiply each side by 4: b² + 4b² = 4r²
- - - - - - - - - - -
0 + 5b² = 4r²
Repeat the
original equation: a² + b² = r²
Subtract the last
two equations: -a² + 4b² = 3r²
Add a² to each side: 4b² = a² + 3r² . <=== ! ! !
-- Start with 86.
-- Subtract 9 the first time. You have 77 left.
-- Subtract 9 the 2nd time. You have 68 left.
-- Subtract 9 the 3rd time. You have 59 left.
-- Subtract 9 the 4th time. You have 50 left.
-- Subtract 9 the 5th time. You have 41 left.
-- Subtract 9 the 6th time. You have 32 left.
-- Subtract 9 the 7th time. You have 23 left.
-- Subtract 9 the 8th time. You have 14 left.
-- Subtract 9 the 9th time. You only have 5 left, so you can't subtract 9 again.
You subtracted it 9 times, and you have 5 left.
So 86 divided by 9 is (9 with remainder 5) .
C = pi x d
So the border is about 3.1 x 20 = 62 inches
Answer:
-3n-3n2+5
Step-by-step explanation:
You can use Keep Change Change in order to simplify the problem
