Answer:
a.
radius [r]=breadth[b]=4in
length [l]=7in
now
[C]area 1/4 th circle +area of 1/4th circle= semi circle =1/2×πr²h=1/2×π×4²=8πin²=25.13in²
area of rectangle [A]=l×b=7×4=28in²
total area =A+C=28in²+25.13in²=53.13in²
Explanation:
b.
height [h] of triangle =12-4=8cm
base[b] of triangle= 12-3.5-3.5=5cm
area of triangle [A]=1/2×b×h=½×8×5=20cm²
again
length of square [L]=12cm
area of square [S]=L²=12²=144cm²
Area of shaded region=S-A=144-20=124cm²