Answer:
C
Step-by-step explanation:
i am smart
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.
Answer:
97.98
Step-by-step explanation:
The area of the parallelogram PQR is the magnitude of the cross product of any two adjacent sides. Using PQ and PS as the adjacent sides;
Area of the parallelogram = |PQ×PS|
PQ = Q-P and PS = S-P
Given P(0,0,0), Q(4,-5,3), R(4,-7,1), S(8,-12,4)
PQ = (4,-5,3) - (0,0,0)
PQ = (4,-5,3)
Also, PS = S-P
PS = (8,-12,4)-(0,0,0)
PS = (8,-12,4)
Taking the cross product of both vectors i.e PQ×PS
(4,5,-3)×(8,-12,4)
PQ×PS = (20-36)i - (16-(-24))j + (-48-40)k
PQ×PS = -16i - 40j -88k
|PQ×PS| = √(-16)²+(-40)²+(-88)²
|PQ×PS| = √256+1600+7744
|PQ×PS| = √9600
|PQ×PS| ≈ 97.98
Hence the area of the parallelogram is 97.98