Answer:
55%
Explanation:
We need to first find the total length of the side.
let remaining length be x
perimeter= 40cm
4 (s)=perimeter
4(7+x)=40
28+4x=40
4x=40-28=12
4x=12
x=12/4=3
total length= 7+3= 10cm
4+y= 10=
y=6
therefore, area of square= s*s= 10*10=100cm²
find areas of the two triangles (unshaded).
1/2*3*10= 15cm²
1/2*6*10= 30 cm²
15/100*100= 15%
30/100*100= 30%
shaded percentage= 100-(15+30)
= 100-45
= 55%