Question

"Question 3 The shape of a garden is rectangular in the middle and semi circular at the ends as shown in the diagram. Find the area and the perimeter of the garden [Length of rectangle is 20 − (3.5 + 3.5) metres]
Class 8 Mensuration Page 171"

Answer 1

Answer:

The shape of a garden is rectangular in the middle and semi circular at the ends as shown in the diagram. Find the area and the perimeter of the garden. [Length of rectangle is 20 − (3.5 + 3.5) metres]

Explanation:

Total area of the garden = Area of the rectangular portion + The sum of the areas of the pair of semi-circles

=l×b+2× ½ πr²

=(13×7)m²+( 2× ½×22/7×3.5×3.5)m²

=(91+38.5)m²

=129.5m²

Perimeter of the garden =2× length of rectangular portion + circumference of the circle

=( 2×13+2×22/7×3.5)m

=(26+22)m=48m.

Answer 2

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Total area of the garden = Area of the rectangular portion + The sum of the areas of the pair of semi-circles

$l.b + 2 \times \frac{1}{2}\pi {r}^{2}$

$= (13 \times 7) {m}^{2} +$

$(2 \times \frac{1}{2} \times \frac{22}{7} \times 3.5 \times 3.5) {m}^{2}$

$= (91 + 38.5) {m}^{2} = 129.5 {m}^{2}$

Perimeter of the garden =2× length of rectangular portion + circumference of the circle

$= (2 \times 13 + 2 \times \frac{22}{7} \times 3.5)m$

$= (26 + 22)m = 48m$