Area of a sector question

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This may be a dumb question,

but in the question attached i don't understand how πx²/3 is the answer, can someone tell me where i'm going wrong

if we calculate the area of the sector by ½ r² ∅ then i did ½x²(120), which i calculated as 60x²

Thanks

Reply 1

ghostwalker

17

Original post by Jessinoch

Attachment not found

This may be a dumb question,

but in the question attached i don't understand how πx²/3 is the answer, can someone tell me where i'm going wrong

if we calculate the area of the sector by ½ r² ∅ then i did ½x²(120), which i calculated as 60x²

Thanks

In the formula for the area,

\frac{1}{2}r^2\theta

, theta is in radians.

Reply 2

elliot-99

6

The question is working in radians not degrees. So feta is 2π/3 (which is 120degrees in radians). So 1/2 * 2π/3 * x² = the given answer of πx²/3

Reply 3

RogerOxon

21

Original post by Jessinoch

This may be a dumb question,

but in the question attached i don't understand how πx²/3 is the answer, can someone tell me where i'm going wrong

if we calculate the area of the sector by ½ r² ∅ then i did ½x²(120), which i calculated as 60x²