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8 votes
The drawing shows a semicircular window separated into 3 sections of coloredglass.RedGreen +Green40°40°18"Approximately how many square inches of the tinted glass are red?

User Ronrun
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1 Answer

23 votes
23 votes

Area of the circle = pi*r~2

Area = 3.14* 7.5^2

Area = 176.6

A semiclrcle is only half the area

Area of the semicircle = 176.6/2

= 88.31

I'll use proportions to find the area of the red region

red region = 100°

88.31 in^2 ------------------------ 180°

x ------------------------ 100°

x = 49 in^2

This is the result:

The area of the red section = 49 in^2