Question

http://prntscr.com/iay8vl

Answer 1

@Vocaloid

Answer 2

area of shaded region = area of the square - area of the circle

the area of the square is (side)^2
the area of the circle is pi * r^2 where the radius is 5

Answer 3

Ok so the answer is B?

Answer 4

please read what I wrote carefully

Answer 5

So for the saquare we have to do 10 times 2 which is 20?

Answer 6

the area of a square is (side)^2 where the 2 is an exponent not multiplication

Answer 7

ok so the area of the square is 10^2

Answer 8

good, keep going

Answer 9

whats pi tho?

Answer 10

pi is approximately 3.14

Answer 11

ok so we have to do 3.14 times 5^2?

Answer 12

yes

Answer 13

78.5

Answer 14

good, and 100 - 78.5 = ?

Answer 15

21.5

Answer 16

good, that's answer D

Answer 17

http://prntscr.com/iayd51

Answer 18

same thing as before, just using side length 8 and radius 4

Answer 19

ok gimme time to find answer

Answer 20

ok so for 8^2

Answer 21

then we do 3.14*8^2

Answer 22

radius is 4 not 8

Answer 23

(since the radius of the circle is 1/2 the side of the square)

Answer 24

ok so 3.14*8^4

Answer 25

pi * r^2

pi * (4)^2

Answer 26

50.24

Answer 27

good, now we just subtract

8^2 - 50.24

Answer 28

13.76

Answer 29

good, so c

Answer 30

http://prntscr.com/iayhsu

Answer 31

shaded area = (big circle area - small circle area)

as usual, area of a circle = pi*r^2

to find the radius of the other two circles, we divide diameter/2

so big radius = 10.5/2
small radius = 4.5/2

Answer 32

use this to calculate: area of big circle - area of small circle

Answer 33

Confused lol

Answer 34

calculate the area of the big circle if the big circle has radius 10.5/2

Answer 35

so 3.14*10.5/2^2?

Answer 36

good just be careful with parentheses

3.14*(10.5/2)^2

Answer 37

86.54625

Answer 38

good, now calculate the area of the smaller circle

small radius = 4.5/2

Answer 39

ok so 3.14*(4.5/2)^2

Answer 40

good

Answer 41

15.89625

Answer 42

good, now just subtract big circle area - small circle area

86.54625 - 15.89625 = ?

Answer 43

70.65

Answer 44

good, and that rounds up to 70.7 (A)

Answer 45

which is A

Answer 46

http://prntscr.com/iayq5g

Answer 47

(gonna assume it's a solid piece of glass not a ring)

so it's just area of circle * price of glass per square meter

Answer 48

so the price is 4.60.
What is the area of the ciricle?

Answer 49

pi * r^2 as usual

Answer 50

ok so 3.14*0.8^2

Answer 51

yes

Answer 52

2.0096

Answer 53

good, and that * the price of glass= ?

Answer 54

1.6

Answer 55

oh no sorry

Answer 56

9.24

Answer 57

good, so b

Answer 58

last one:
http://prntscr.com/iaytnd

Answer 59

if we put the two ends of the shape together we get a circle with radius 15

the rectangle has length 50 and width 30

so area of rectangle + area of circle = ?

Answer 60

1500

Answer 61

3.14*15^2

Answer 62

706.5

Answer 63

1500 plus 706.5

Answer 64

good, and that equals...?

Answer 65

2206.5

Answer 66

D

Answer 67

awesome, d

Answer 68

Ok thanks for all the help voca!