Answer
25m^2
and rs 500
Answers
Question:
A kite is made of special paper that costs 40 p per cm² . If BD = 6 cm , AO = 4 cm and CO = 8 cm , find the cost of making the kite.
Answer:
RS. 14.40
OR
RS. 14 and 40 p
Note:
• A kite is a quadrilateral whose adjacent sides are equal.
• Both the diagonals of a kite bisect each other at right angle (ie; at 90°) .
• Area of kite is given as ; A = (D1•D2)/2
where D1 and D2 are the two diagonals of the kite .
• Area of a triangle is given as ; (B•H)/2
where B and H are the base and the height of the triangle respectively.
• RS. 1 = 100 p
Solution :
Method 1 :-
Given:
- BD = 6 cm
- AO = 4 cm
- CO = 8 cm
- Cost of making kite = 40 p per cm²
Thus;
=> AC = AO + CO
=> AC = 4 cm + 8 cm
=> AC = 12 cm
Now,
=> Area of kite ABCD = (D1•D2)/2
=> Area of kite ABCD = (AC•BD)/2
=> Area of kite ABCD = (12•6)/2
=> Area of kite ABCD = 6•6
=> Area of kite ABCD = 36 cm²
Also ,
It is given that;
The cost of making the kite is 40 p per cm² .
Thus,
=> Cost of 1 cm² paper = 40 p
=> Cost of 36 cm² paper = 36 × 40 p
=> Cost of 36 cm² paper = 1440 p
=> Cost of 36 cm² paper = RS. 1440/100
=> Cost of 36 cm² paper = RS. 14.40
=> Cost of 36 cm² paper = RS. 14 and 40 p
Hence,
The cost of making the kite is ;
RS. 14.40
Method 2 :-
Given:
- BD = 6 cm
- AO = 4 cm
- CO = 8 cm
- Cost of making kite = 40 p per cm²
Now,
=> Area of ∆ABD = (BD•AO)/2
=> Area of ∆ABD = (6•4)/2
=> Area of ∆ABD = 3•4
=> Area of ∆ABD = 12 cm²
Also,
=> Area of ∆BDC = (BD•CO)/2
=> Area of ∆BDC = (6•8)/2
=> Area of ∆BDC = 3•8
=> Area of ∆BDC = 24 cm²
Now,
=> Area of kite ABCD = Area of ∆ABD + Area of ∆BDC
=> Area of kite ABCD = 12 cm² + 24 cm²
=> Area of kite ABCD = 36 cm²
Also ,
It is given that;
The cost of making the kite is 40 p per cm² .
Thus,
=> Cost of 1 cm² paper = 40 p
=> Cost of 36 cm² paper = 36 × 40 p
=> Cost of 36 cm² paper = 1440 p
=> Cost of 36 cm² paper = RS. 1440/100
=> Cost of 36 cm² paper = RS. 14.40
=> Cost of 36 cm² paper = RS. 14 and 40 p
Hence,
The cost of making the kite is ;
RS. 14.40
Answer:
the answer to your question is in the picture attached...
hope it helps buddy...
