Step-by-step explanation:
Circumference of a circle is 2piR
C=2piR and R=10
C=2(3.14)(10)
So the circumference is 62.8 cm
The standard equation of a circle is:

where (h,k) is the center and r is the radius.
We need to make an equation of a circle, whose center is (11,-5) with any radius. Therefore, substitute the value.

The bolded part is your answer. Since the radius is not given, we can put any value.
Answer:
x = 20
Step-by-step explanation:
Traingle ABC = Traingle DEC
4x-1×4×5 = x+2×4×5
80x-1 = 2×20x
80x-20x = 2+1
60x = 3
60÷3 = x
x = 20