the area of a circle is 154cm square. find its circumference

Area of a circle = πr²
so 154 = 22/7 x r²
r² = ​154 x 7/22 
r² = 49
r  = 7

than 
Circumfrence = 2​πr
= 2 x 22/7 x 7
= 44 

Hence circumfrence of circle = 44 cm
 

44 cm

area = 154 cm²

154= 22/7 * r²  ( r = radius)
154*7/22 = r²
r² = 49
radius = 7
Circumference = 2* 22/7 * r = 2* 22/7 * 7
= 44 cm

Diameter=8×2=16m diagonal =16 Area of square =[16×16]÷2=128msq