Answer:
x=1, y=2. (1, 2).
Step-by-step explanation:
-3x+10y=17
3x+7y=17
---------------
17y=34
y=34/17
y=2
3x+7(2)=17
3x+14=17
3x=17-14
3x=3
x=3/3
x=1
Answer:
13 batches of cookies
Step-by-step explanation:
12 2/3 ÷ 2/3 = 12.6666667, it's 13 because 2/3 as a decimal is .6666666 and .6666667 is more than 2/3. So you add one to the answer.
Answer:
10.89
Step-by-step explanation:
Circle:
C = TTD
C = TT(6.6)
C = 20.73451151
C = 20.73
Triangle:
A = bh/2
A = 6.6(3.3)/2 6.6/2=3.3
A = 21.78/2
A = 10.89
Shaded Region = 10.89
The area of a polygon is given by the formula Area = ap/2 where a is the length of the apothem and p is the perimeter. The apothem is a line from the center of the polygon perpendicular to a side.
Depending on the formula you know, you can find the length of a side in 1 of 2 ways.
The first way uses a triangle. Using the radius of the polygon you can create 8 congruent triangles. The center angle will be 360 / 8 = 45 and two side lengths of 20. You can find the length of the base using the law of cosines.
c^2 = 20^2 + 20^2 - 2(20)(20)(cos 45)
c^2 = 400 + 400 - 800(cos 45)
c^2 = 800 - 800(cos 45)
c = sqrt(800 - 800(cos 45)
c = 15.31
The second way is to use this formula:
r = s / (2 sin(180 / n))
20 = s / (2 sin(180/8)
(20)(2)sin(22.5) = s
(40)sin(22.5) = s
s = 15.31
We need to calculate the perimeter. As there are 8 sides (8)(15.31) = 122.48
Now we need to calculate the apothem using
a = S / (2 tan (180 / n)
a = 15.31 / (2 tan (180 / 8))
a = 18.48
Now solve for the area
Area = ap/2
Area = (18.48)(122.48)/2
Area = 1131.72
perimeter = 122.48
area = 1131.72
