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## Class 10 (Marathi)

### Course: Class 10 (Marathi)>Unit 11

Lesson 6: Areas of combination of plane figures

# Area of a shaded region

Here's a fun one: find the area of a shaded region where you first determine the area of a square and then the area of a circle. Created by Sal Khan.

## Want to join the conversation?

• This may not sound very smart but why did you multiple 3*3
• Sal multiplied 3 and 3 because the formula for getting area is A = r^2 pi. If our radius is 3, and if part of the formula is r^2, to get the radius to the second power you multiply 3 and 3 .
• at what was that green thing
• It is due to an incomplete answer. Once you finish typing your answer, assuming it is an acceptable form for the particular question, the green guy goes away:)
• Why he didn't multiply it by 4 like:
100 - 4(3^2)pi? isn't this going to give us all four sides? o.O #confused

PS: Oh I get it, I get it now :D. (3^2)pi will give us the entire area of full circle :D
• What if your book doesn't give the area of the shape?
• what is this website he's using called?
• it still doesn't make sence.