Question

What is the area of the given composite figure, using 3.14 for π. Round to the nearest tenth. (*Hint- find the area of the rectangle and semi-circle then add them together)

Question 1 options:

187.9 cm²


356.9 cm²


433.9 cm²


110.9 cm²

Answer 1

356.9 cm² is the answer.

Explanation:

The area of the figure can be derived by adding the area of the rectangle and the area of half circle or semicircle.

Length of rectangle = 20 cm

Width of rectangle = 14 cm

So, area is =
`20*14=280` cm square

Now for semicircle, the radius will be =
`(14)/(2)=7` cm

The area can be found as :
`(1)/(2)\pi r^(2)`

=
`(1)/(2)(3.14*7*7)`

= 76.93 cm square

Now adding both the areas, we get the complete area of the figure.

Total area =
`280+76.93=356.93` cm square ≈ 356.9 cm square.

Answer 2

The area of the rectangular part = 14 x 20 = 280 sq. cm

The area of the half circle = 1/2 (3.14 x 7^2) = 76.9 sq. cm.

Total area = 280 + 76.93 = 356.9 cm^2