Answer:
4. Option 3: 65.1 cm^2
5. Option 3: 3.4 inches^2
Step-by-step explanation:
Question 4
:
We can see that there is a rectangle and a half circle in the picture.
So we will find the area of both separately
For the area of rectangle
Area=length*width
=8*5
=40 cm^2
We know that the line which is representing the diameter has length 8 cm
To find the radius
r=d/2
=8/2
=4 cm
As we cannot find the area of half circle, we will find the area of full circle and will divide it in half.
So,
area= πr^2
=3.14*(4)
=3.14*16
=50.24 cm^2
Area of half circle=(Area of full circle)/2
=50.24/2
=25.12 cm^2
So the area of shape will be
Area of rectangle+area of half circle
=40 cm^2+25.12 cm^2
=65.12 cm^2
Rounding off to nearest 10 will give 65.1 cm^2
So, option 3 is the correct answer ..
Question 5
:
To find the area of shaded region we have to find the area of circle and area of square in which it is inscribed
So,
area of circle= πr^2
=3.14*(2)^2
=3.14*4
=12.56 inches^2
And to find the area of square we need one of its side, we can clearly see that the diameter of circle will be equal to the side of square
So,
Side of square=s=r*2
=2*2
=4 inches
Area of square=s^2
=4^2
=16 inches^2
To find the area of shaded region we have to subtract the area of circle from the area of square
So,
Area of Shaded Region=Area of Square-Area of Circle
=16-12.56
=3.44 inches^2
Rounding off to the nearest 10 will give 3.4 inches^2 ..
So, option 3 is the correct answer ..
