Q17 of 69 Page 238

An umbrella is made by stitching 12 triangular pieces of cloth, each measuring (50 cm x 20 cm x 50 cm). Find the area of the cloth used in it.

Let the sides of the triangle be,


a = 50 cm


b = 20 cm


And


C = 50 cm


Now, let us find the value of s:


s =


=


= 60 cm


We know that,


Area =


Area of one triangular piece of cloth =


=


=


=


= 10 × 10 × 2


= 200


= 200 × 2.45


= 490 cm2


Therefore,


Area of one piece of cloth = 490 cm2


Hence,


Area of 12 pieces of cloth = 12 × 490


= 5880 cm2


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(i) The area of the triangle, correct to 2 places of decimal


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