The seamstress can cut 36, 15-inch pieces of ribbon from 5 rolls of 9 foot long ribbon.
Explanation:
a. The line joining the midpoints of the parallel bases is perpendicular to both of them. It is the line of symmetry for the trapezoid. This means the angles and sides on one side of that line of symmetry are congruent to the corresponding angles and sides on the other side of the line. The diagonals are the same length.
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b. We observe that adjacent pairs of points have the same x-coordinate, so are on vertical lines, which have undefined slope. KN is a segment of the line x=1; LM is a segment of the line x=3. If the trapezoid is isosceles, the midpoints of these segments will be on a horizontal line. The midpoint of KN is at y=(3-2)/2 = 1/2. The midpoint of LM is at y=(1+0)/2 = 1/2. These points are on the same horizontal line, so the trapezoid <em>is isosceles</em>.
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c. We observed in part (b) that the parallel sides are KN and LM. The coordinate difference between K and L is (1, 3) -(3, 1) = (-2, 2). That is, segment KL is the hypotenuse of an isosceles right triangle with side lengths 2, so the lengths of KL and MN are both 2√2.
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For part (c), we used the shortcut that the hypotenuse of an isosceles right triangle is √2 times the leg length.
8x -2y + x+x
simply combine like terms
8x+ x + x= 10x
therefore
10x-2y is equivalent
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Hi there!
The formula to find the are of a circle is :
a =
r²
The formula to find the circumference of a circle is :
c = 2
r
In order to use the area formula, you need to figure out what the radius (r) is.
If we solve for "r" in the circumference equation, we have :
r = c ÷ (2
)
Now we use this to replace "r" in the area formula :
a =
( c ÷ (2
))²
When we simplify this we get :
a = c² ÷ 4
Now you can put your value of "c" into this equation and find "a".
*Remember,
is about 3.1416.
Solving for "a" :
a = c² ÷ 4
a = 28² ÷ 4
28² = 28 × 28 = 784
a = 784 ÷ 4
4
= 4 ×
= 12.56637061435917
a = 784 ÷ 12.56637061435917
a = 62.38873769202297cm²
You need to round to the nearest square centimeter, which means that you need to round to the nearest whole number :
a = 62cm²
There you go! I really hope this helped, if there's anything just let me know! :)