Question

Find the length of a 90° arc of a circle with a diameter of 10 m​

Answer 1

Answer:

7.85 m (3 significant figures)

Step-by-step explanation:

Formula:   arc length = $2\pi r(\frac{\theta}{360} )$

The radius of a circle is half the diameter, so r = 10 ÷ 2 = 5

Therefore, arc length = 2 x $\pi$ x 5 x $(\frac{90}{360} )$

                                    = $\frac{5}{2}\pi$

                                    = 7.853981634...

                                    = 7.85 m (3 significant figures)