Solution :-
The area of a semi circle is 19.25
We know that,
Area of semicircle = 1/2(πr²)
Therefore,
19.25 = 1/2 * 22/7 * r²
19.25 = 22/14 * r²
19.25 * 14/22 = r²
269.5/22 = r²
12.25 = r²
r = √12.25
r = 3.5 cm
Thus, The radius of the given semicircle is 3.5 cm
Therefore,
Diameter of the given circle = 2 * Radius
Diameter = 2 * 3.5 = 7 cm
Hence, The diameter of the given circle is 7 cm