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Find the area of a sector, whose perimeter is 40 cm, and the radius is 8 cm.

User Bhakta
by
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1 Answer

4 votes

Answer:

96 cm²

Explanation:

From the question,

s = (2πr∅/360)+2r................. Equation 1

Where s = Perimeter of a sector, r = radius, ∅ = angle subtend by the sector at the center of the circle.

Given: s = 40 cm, r = 8 cm

Constant : π = 3.14.

Substitute into equation 1 and solve for ∅

40 = (2×8×3.14×∅/360)+(2×8)

40 = (50.24∅/360)+16

40-16 = 50.24∅/360

50.24∅/360 = 24

50.24∅ = 24×360

50.24∅ = 8640

∅ = 8640/50.24

∅ = 171.97°

Area of a sector (A') = ∅πr²/360

A' = 171.97×3.14×8²/360

A' = 95.997

A' ≈ 96 cm²

User Tomas Creemers
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5.5k points