Question

Calculate the amount of paint needed to cover the following door:

Answer 1

Answer:

Step-by-step 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.