Question

206
Universal Mathematics
25 cm
25 cm
25 cm
25 cm
Fig. 13.6
3. Find the side of a square tile whose perimeter is 176 cm.
4. Kajal wants to seal a box in the shape of a regular octagon of side 15 cm
using tape. Find the length of the tape required.
5. Acopper wire is bent to form the shape as shown in Fig. 13.6. If the same
wire is bent again in the form of a regular pentagon, find the side of the
pentagon
6. Riva got a border to be stitched along the edges of a quilt cover. She gave
the 30-metre border to the tailor. If the quilt cover is 8.5 m long and 6.25 m
wide, find whether the border will be enough for the quilt or the tailor
will require more
7. The owner of a skating rink wants to have four rounds of rope around it. If the
rink is 65 m by 12 m, find the length of the rope required. Also find the cost
of fencing if the rope costs 212 per m.
S. Jasmeet is putting lace around a pillow cover, which is 40 cm long and 25 cm
broad. She has also designed a flower made of lace in one corner. Find the
total length of the lace required to make six pillow covers if the flower on
each pillow requires an extra 15 cm of lace.​

Answer 1

Answer:

Step-by-step explanation:

4. As given : Kajal wants to seal a box in the shape of a regular octagon of side 15 cm using tape .

From that we get Length of each side of regular octagon = 15 cm

And

Length of tape required to seal the regular octagon shaped box = Perimeter of regular octagon

And

We know Perimeter of regular octagon = 8 ( Side of regular octagon ) , So

Perimeter of our regular octagon shaped box = 8 × 15 = 120 cm

So,

Length of tape required to seal the regular octagon shaped box = 120 cm ( Ans )

7. perimeter of skating rink = 2(l+b) = 2(65+12)m =154m

length of rope required=4 X perimeter =4 X 154m = 616m

cost of fencing= Rs 12 X 616= Rs 7392

or

The cost of fencing if the Rope costs Rs 12 per metre is Rs.7392

Step-by-step explanation:

Length = 65 m

Breadth = 12 m

Perimeter = 2(l+b)=2(65+12)=154 m

So, length of rope for 1 round = 154 m

Length of rope for 4 rounds =  

Cost of fencing 1 m = Rs.12

Cost of fencing 616 m =  

Hence the cost of fencing if the Rope costs Rs 12 per metre is Rs.7392

#Learn more:

A farmer has a rectangular field of length 250 m and breadth 150m. He wants to fence it with 3

rounds of rope. What is the total length of rope he must buy? Also find the total cost if one metre of

rope costs 7.​