The complete question is as follows.
The equation a =
can be used to determine the area , <em>a</em>, of a trapezoid with height , h, and base lengths,
and
. Which are equivalent equations?
(a) 
(b) 
(c)
= 
(d) 
(e)
= h
Answer: (a)
; (d)
;
Step-by-step explanation: To determine
:
a = 
2a = (
)h


To determine h:
a = 
2a = 
= h
To determine 
a = 
2a = 


Checking the alternatives, you have that
and
= h, so alternatives <u>A</u> and <u>D</u> are correct.
If a wheel makes a full turn, it will have traveled the entire distance around that wheel. After 3 revolutions, it should have traveled 3 times its circumfrence.
The circumfrence of a circle is equal to the diameter times pi. (about 3.14)
21 × 3.14 = 65.94 = circumfrence = 1 revolution
3 revolutions = = 65.94 × 3 = D. 197.82 in.
I don't really get what you are asking for. Can you clarify it?
3 x 2 is 6. 6 x 5 is 30.. There you go, the answer is 30.