The correct option is D.
Option A. isn't even about quadrilater, so we can immediately discard it.
Option B. statement is true, but has nothing to do with the point of the question. In fact, it is true that every square is in particular a rectangle, but in turn every rectangle is a parallelogram. So, there's no counterexample here
Option C. is false, because a dart is a parallelogram: both of its opposite sides are parallel.
Option D. finally presents a counterexample. In fact, The two bases of a trapezoid are parallel, but the two other sides are not. So, a trapezoid is not a parallelogram, even though it has a pair of parallel sides. This is way, in order to be a parallelogram, it is necessary for the quadrilateral to have two pairs of parallel sides.
Answer:
120°
Step-by-step explanation:
Add the 2 opposite angles to find the exterior angle.
50° + 70° = 120°
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Answer:

Step-by-step explanation:
the answer is :- .

Answer:
1
+
sec
2
(
x
)
sin
2
(
x
)
=
sec
2
(
x
)
Start on the left side.
1
+
sec
2
(
x
)
sin
2
(
x
)
Convert to sines and cosines.
Tap for more steps...
1
+
1
cos
2
(
x
)
sin
2
(
x
)
Write
sin
2
(
x
)
as a fraction with denominator
1
.
1
+
1
cos
2
(
x
)
⋅
sin
2
(
x
)
1
Combine.
1
+
1
sin
2
(
x
)
cos
2
(
x
)
⋅
1
Multiply
sin
(
x
)
2
by
1
.
1
+
sin
2
(
x
)
cos
2
(
x
)
⋅
1
Multiply
cos
(
x
)
2
by
1
.
1
+
sin
2
(
x
)
cos
2
(
x
)
Apply Pythagorean identity in reverse.
1
+
1
−
cos
2
(
x
)
cos
2
(
x
)
Simplify.
Tap for more steps...
1
cos
2
(
x
)
Now consider the right side of the equation.
sec
2
(
x
)
Convert to sines and cosines.
Tap for more steps...
1
2
cos
2
(
x
)
One to any power is one.
1
cos
2
(
x
)
Because the two sides have been shown to be equivalent, the equation is an identity.
1
+
sec
2
(
x
)
sin
2
(
x
)
=
sec
2
(
x
)
is an identity
Step-by-step explanation: