Question

The shape of the top of a table in a restaurant is that of a segment of a circle with centre $O$ and $\angle BOD={90}^{\circ }$. If $BO=OD=60cm$. The perimeter of the table is (Take $\pi =3.14$)

• A. $402$ $cm$
• B. $402.6$ $cm$
• C. $401$ $cm$
• D. $400$ $cm$

Answer 1

The correct option is B $402.6$ $cm$

Given that $\angle BOD=90$, so the top of the table is $\frac{3}{4}$ of a circle of radius $60cm$. Perimeter of the table $=\left(\frac{3}{4}\times 2\pi r+2r\right)cm=\left(\frac{3}{4}\times 2\times 3.14\times 60+2\times 60\right)cm$
$=(90\times 3.14+120)cm=402.6cm$.