Question

Please help with circles

Answer 1

We need to find out the total length of wire needed to make this design. We can do this by finding out the perimeter of square and Circle and finally adding the lengths of the four 15cm wire used .

Given data:-

• length of side of square= 70cm
• diameter of Circle= 40cm , r = 20cm
• 15cm four wires

Perimeter of the square:-

`\longrightarrow p_s = 4(side) \\`

`\longrightarrow p_s = 4(70cm) \\`

`\longrightarrow p_s = 280cm \\`

Perimeter/circumference of the circle:-

`\longrightarrow p_c = 2\pi r \\`

`\longrightarrow p_c = 2(3.14)(20cm) \\`

`\longrightarrow p_c = 125.71 cm \\`

Additionally length of four wires would be 15cm*4 = 60cm .

So , total length of the wire required,

`\longrightarrow l =( 125.71 + 280+60)cm \approx \boxed{466\ cm}\\`

and we are done!

Answer 2

≈ 466 cm

Explanation:

the total length of wire required is

outside sides of square + 4 straight pieces + circumference of circle

= (4 × 70) + (4 × 15) + (π d ← d is the diameter )

= 280 + 60 + 40π

= 340 + 125.66

= 465.66

≈ 466 cm ( to the nearest cm )