The area is 20.5632 cm sq.
Lets break it down:
Triangle- the area of a triangle is bh/2 (base×height÷2). If we plug in the numbers, the base is 4.8 and the height is 4.8. 4.8×4.8= 23.04÷2= 11.52
Semi circle- the area of the semi circle is pi×radius×radius. We have the diameter (4.8) so we would need to divide 4.8 by 2 to get 2.4. 2.4×2.4×3.14= 18.0864. We need to divide that by 2 because its a semi circle so 18.0864÷2= 9.0432
11.52+9.0432= 20.5632 cm sq.
hope this helps!