Percentage of the area shaded = 55%
Solution:
Perimeter of the square = 40 cm
Each side of the square = = 10 cm
Area of the square =
= 10²
= 100
Total area of the square = 100 cm²
The unshaded portion is two triangles.
Base of the smaller triangle = 10 cm – 7 cm = 3 cm
Height of the smaller triangle = 10 cm
Area of the smaller triangle =
Area of the smaller triangle = 15 cm²
Base of the larger triangle = 10 cm – 4 cm = 6 cm
Height of the larger triangle = 10 cm
Area of the larger triangle =
Area of the larger triangle = 30 cm²
Area of the shaded portion = Area of the square – Area of the smaller
triangle – Area of the larger triangle
= 100 cm² – 15 cm² – 30 cm²
Area of the shaded portion = 55 cm²
Percentage of the area shaded =
Percentage of the area shaded = 55%
