An umbrella is made by stitching 10 triangular pieces of cloth of two different colors (see Fig. 12.16), each piece measuring 20 cm, 50 cm and 50 cm. How much cloth of each color is required for the umbrella?
Perimeter of each triangular piece of cloth = 50 + 50 + 20
Semi perimeter of each triangular piece of cloth = 
=
= 60cm
Using Heron’s formula,
Area of 
= 
= 
= 
= 
cm2
Area of triangular piece = 5* 
=1000
cm2
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