Question

the area of circle is equal to perimeter of circle when its radius is what

Answer 1

Answer:

The radius is half of its Diameter

Answer 2

Since the area is equal to the circumference (perimeter of circle),

$\sf {Circumference = 2\pi R}\\\\\\\sf {Area = \pi R^{2}}\\\\\\\sf {2\pi R=\pi R^{2}}\\\\\\\sf {R=2}$

Checking

$\sf {2 \pi R =\pi R^{2}}\\\\\\\sf {2 \times 2 = 2^{2}}\\\\\\\sf {4 = 4}$