Question

Each small square on the grid is 1 in².

Which estimate best describes the area of this figure?


10 in²

15 in²

20 in²

35 in²

Answer 1

20 in²

Explanation:

The figure is an irregular polygon. The blue coloured part is the area covered by the polygon.

To determine the area covered by the irregular polygon, we will count the number of small squares under the area covered by the irregular polygon. There are complete and incomplete small squares.

Each complete small square is 1 in²

There are 10 small complete squares. The are covered by the 10 small complete squares

= 10 × 1 in² = 10 in²

There are 20 incomplete small squares. The area covered by the 20 incomplete small squares = 20/2 × 1 in² = 10×1 in² = 10in².

Estimated total area covered by the irregular polygon is

10 + 10 = 20 in².