Answer:
C ; A
Step-by-step explanation:
<u>Question 30:</u>
Perimeter is the sum of all sides.
Perimeter for a recatngle can be found with the formula:
2(L+W)
Length is 7
Width is 4
Plug our values in.
2(7+4)
2(11)
22
Answer C
<u>Question 31:</u>
Circumference of a circle can be found with the formula:
πd.
Diameter of the given circle is 6.
Plug it in
6π
Round π to 3.14
6(3.14)
18.84
Answer A
Answer:
the answer should be 8.9
you square 12 and square the 8 and subtract them by each other
Answer:
C
Step-by-step explanation:
Anything less than 5 rounds down while 5 and anything more rounds up. Therefore...
15.3 rounds to 15
7.9 rounds to 8
7.4 rounds to 7
So, his answer is reasonable.
Answer:
see explanation
Step-by-step explanation:
Using the double angle identity for sine
sin2x = 2sinxcosx
Consider left side
cos20°cos40°cos80°
= 
(2sin20°cos20°)cos40°cos80°
= 
(2sin40°cos40°)cos80°
= (sin80°cos80° )
= 
(2sin80°cos80° )
= . sin160°
= . sin(180 - 20)°
= . sin20°
= 
= right side , thus proven
