Answer:
The dimensions are:
by 
Step-by-step explanation:
The area of the rectangle is given as

The factored form of this quadratic trinomial gives the dimensions of the rectangle.
We factor 3 first to obtain;

We split the middle term to get;

We factor within the parenthesis to get;

We factor further to get;

The dimensions are:
by 
Then the perimeter will be

Answer:
100
Step-by-step explanation:
they are vertical angles therefore, they have the same measure.
Answer:
=14.69km²
Step-by-step explanation:
We can use the Hero's formula to calculate the area
A= √(s(s-a)(s-b)(s-c))
s is obtained by adding the lengths of the three sides of the triangle and then dividing by 2, a, b and c are the ides of the triangle.
S=(5+6+7)/2
=9
A=√(9(9-6)(9-5)(9-7))
=√(9×3×4×2)
=√216
=14.69km²