Is anyone good at Calculating Missings sides and angles? Cause this is the problem i have.

solution: - consider a rectangle   with dimensions 12cm×2cm

then its area =   length×breadth = 12cm × 2cm =24 sqcm

now consider a circle with radius r= 8 cm

we know that area of a circle =

as the rectangle   is lying inside the circle as in figure

the area of the remaining part(or the shaded region)   =area of circle -area of rectangle

answer- the area of the shaded region is