Question

Please help with this

Answer 1

Step-by-step explanation:

As a square with a perimeter of 40cm.

It means each side of the square has a length 10cm.

i.e.

P = 10+10+10+10

  = 40cm

and

The total Area of the diagram of square = 10 × 10 = 100 cm²

Calculating the Shaded Area:

As the upper length of shaded side of the shape inside square = 7 cm

so the non-shaded length of upper side of the square = 10-7 = 3cm

so

the area of left sided un-shaded triangle = 1/2 * b * h

                                                                    = (3 * 10)/2

                                                                   

Similarly, the right sided length of shaded side inside the square = 4 cm

so the non-shaded right sided-length of the square = 10-4 = 6cm

the area of right sided un-shaded triangle = 1/2 * b * h

                                                                    = (10 * 6)/2

Therefore, the area inside the square that is shaded is:

$\left(10\:\times 10\right)\:-\:\frac{\left(3\:\times \:10\right)}{2}\:-\:\frac{\left(10\times \:6\right)}{2}$

$=\left(10\times \:10\right)-45$            ∵ $-\frac{3\times \:10}{2}-\frac{10\times \:6}{2}:\quad -45$

$=100-45$

$=55$  cm²  

So,  the percentage of the total area inside the square

that is shaded = 55%.

And the percentage of the total area inside the square

that is non-shaded = 100 - 55 = 45 cm²   ∵ Total Area - shaded Area

Therefore, the percentage of the total area inside the square

that is shaded = 55%.