### Instruction: In a triangle, the area is numerically equal to the perimeter. What is the radius of the inscribed circle?
$\text{(A) } 2\quad \text{(B) } 3\quad \text{(C) } 4\quad \text{(D) } 5\quad \text{(E) } 6$.### Response: I know that the area of a triangle is equal to the product of its semiperimeter and the radius of its inscribed circle, by the formula $A = rs$.
So, if the area and the perimeter are equal, then $rs = 2s$, which implies that $r = 2$.
Therefore, the radius of the inscribed circle is 2 units.