A circle has infinit lines of symmetry. They pass through the centre of the circle and are the circle's diameter.
Hope this helps! (:
Answer:
The following are the solution to the given points:
Step-by-step explanation:
for point A:


The set A is not part of the subspace 
for point B:


The set B is part of the subspace
for point C:

In this, the scalar multiplication can't behold

∉ C
this inequality is not hold
The set C is not a part of the subspace
for point D:

The scalar multiplication s is not to hold
∉ D
this is an inequality, which is not hold
The set D is not part of the subspace 
For point E:

The
is the arbitrary, in which
is arbitrary

The set E is the part of the subspace
For point F:

The
arbitrary so, they have
as the arbitrary 
The set F is the subspace of 
Answer:
Answer for A
Step-by-step explanation:
I don't know about B , Sorry for that.
7.87 is what i got :) good luck!!
Answer:
Yes
Step-by-step explanation:
Triangle inequality theorem states that a triangle can exist if
a + b > c; a + c > b; b + c > a
a = 2; b = 10; c = 11
2 + 10 = 12; 12 > 11.
2 + 11 = 13; 13 > 10.
10 + 11 = 21; 21 > 2.