Area of a Semi Circle

Jesse used rope to stake a circular region in which to plant a garden. The diameter of the region is 20 inches. What is the approximate area of half of the garden?

• 31.4 in²

• 314 in²

• 157 in²

• 628 in²

what is the formula for finding the area of a semi-circle

• A = π r²

• C = π r²

• A = π r² / 2

• A = 2 π r

Mrs. Wilson placed the welcome mat shown below on her front door step. What is the area of her welcome mat in square feet? Leave in terms of π.

• 2π

• 8π

• 10π

• 4π

What is the area of this semi circle? 

• 100.5 square cm

• 25.1  square cm

• 50.3 square cm

• 12.6 square cm

Determine the area of the semicircle above.

Mathematical Equivalence

ON

what is the formula for finding the area of a semi-circle

• A = π r²

• C = π r²

• A = 1/2 π r²

• A = 2 π r

• A = 2π r²

A semi-circle is half of a circle. How should the Area formula be changed so that it gives you the Area of a Semi-Circle?

Find the area of the composite figure.

• 100

• 400

• 137.5

• 175

What is the area of this composite shape? (Use 3.14 = π and round to the nearest tenths place)

• 21

• 19.2

• 40.2

• 42

The West Lighthouse lights up how much more area than the East Lighthouse?