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Determine the length of the arc that subtends an angle of 2.8 radians at the centre of a circle with a radius 12cm.

A. 13.3 cm
B. 33.6 cm
C. 16.8 cm
D. 148.0 cm

User Gmoniey
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1 Answer

4 votes

Answer:

B. 33.6 cm

Explanation:

To find determine the length of an arc that subtends an angle of 2.8 radians at the centre of a circle with radius 12 cm, we will follow the steps below;

First write down the formula for calculating length of an arc

If the angle is measured in degree, then the formula for calculating the length of an arc is :

length of an arc = Ф/360 × 2πr

but if the angle is measured in radians, then the formula for calculating length of an arc will be:

length of an arc = r Ф

where r is the radius and Ф is the central angle in radians

In the case of the question given to us, the angle is given in radians, so we will use the second formula

angle Ф = 2.8

radius = 12 cm

length of an arc = r Ф

=12 × 2.8

=33.6

Length of the arc = 33.6 cm

User Ari M
by
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