Question

Please help with this

Answer 1

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\:* 10\right)\:-\:(\left(3\:* \:10\right))/(2)\:-\:(\left(10* \:6\right))/(2)`

`=\left(10* \:10\right)-45` ∵
`-(3* \:10)/(2)-(10* \: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%.