Q1 of 33 Page 12

Find the area of a triangle in which
(i)  a = b = c = 4 cm
(ii) In right angled triangle, hypotenuse is 13 cm and one side is 5 cm.

(i) Area of a equilateral triangle =  =  ´ (4)2 = 6.928 cm2                                                                     
(ii) Area of right angled triangle = ´ base × height
Hypotenuse = 13cm, one side = 5cm
(Hypotenuse)2= (one side)2 + (other side)2
  132 = x2 + 52
  ⇒ x = 12 cm
Area of the right angled triangle=  ´ 12 ´ 5 = 30 cm2.

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