Mathematics

An umbrella has 8 ribs which are equally spaced. Assuming umbrella to be a flat circle of radius 45 cm, find the area between the two consecutive ribs of the umbrella.

Circles

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Answer

There are 8 ribs and total angle in a circle = 360°.

So, angle subtended by each rib = $\dfrac{360°}{8}$ = 45°.

Area between two consecutive ribs = Area of a rib

We know that,

Area of sector of angle θ and radius r = $\dfrac{θ}{360°} \times πr^2$

Substituting values we get :

$\text{Area subtended by a rib} = \dfrac{45}{360} \times \dfrac{22}{7} \times 45^2 \\[1em] = \dfrac{1}{8} \times \dfrac{22}{7} \times 2025 \\[1em] = \dfrac{44550}{56} \\[1em] = \dfrac{22275}{28} \text{ cm}^2.$

Hence, area between two consecutive ribs = $\dfrac{22275}{28}$ cm².

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Mathematics

An umbrella has 8 ribs which are equally spaced. Assuming umbrella to be a flat circle of radius 45 cm, find the area between the two consecutive ribs of the umbrella.

Circles

Answer

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Mathematics

An umbrella has 8 ribs which are equally spaced. Assuming umbrella to be a flat circle of radius 45 cm, find the area between the two consecutive ribs of the umbrella.

Circles

Answer

Related Questions

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To warn ships for underwater rocks, a lighthouse spreads a red coloured light over a sector of angle 80° to a distance of 16.5 km. Find the area of the sea over which the ships are warned.(Use π = 3.14)

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(i) the area of that part of the field in which the horse can graze.
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