56.5k views
3 votes
Calculate the amount of paint needed to cover the following door:

Note: You do not paint the window on the inside.

Calculate the amount of paint needed to cover the following door: Note: You do not-example-1
User Joannes
by
5.0k points

1 Answer

4 votes

Answer:

Explanation:

The door is shape is a combination of a rectangle and a semicircle with a square window.

Area of the door = Area of rectangle + area of a semi circle

Area of a rectangle = Length * Width (LW)

area of a semicircle = πr²/2 where r is the radius of the semi circle.

Given the length of the rectangle = 2m and its width = 1m

Area of rectangle = 2*1 = 2m²

Given the radius of the semicircle = 1/2 m

Area of the semi circle = π(0.5)²/2

= 0.25π/2

= 0.785/2

Area of the semicircle= 0.3925m²

Area of the door = 2+0.3925

Area of the door = 2.3925m²

Since we are not to paint the window, we will subtract the area of the window from the total area.

Area of the window = area of a square = 0.2*0.2

= 0.04m²

Area to be painted = Area of door - Area of the square

Area to be painted = 2.3925m² - 0.04m²

Area to be painted = 2.3535m²

Note that there was no enough information for us to calculate the amount of paint needed but knowing the area of the part to be painted can guide us.

User Juri
by
5.3k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.