Q10 of 69 Page 238

The base of an isosceles triangle measures 80cm and its area is 360cm2 . Find the perimeter of the triangle.

Let us assume be an isosceles triangle and let AL perpendicular BC



It is given that,


BC = 80 cm


Area of triangle ABC = 360 cm2


We know that,


Area of triangle =


= 360 cm2


= 360 cm2


= 360 cm2


=


= 9 cm


Now,


BL =


= (


= 40 cm


a =


=


=


=


= 41 cm


Therefore,


Perimeter of the triangle = (41 + 41 + 80) = 162 cm


More from this chapter

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8

Two sides of a triangular field are 85m and 154m in length and its perimeter is 324m. Find:

(i) The area of the field and


(ii) The length of the perpendicular from the opposite vertex of the side measuring 154m.

 9

Find the area of an isosceles triangle each of whose equal sides measures 13cm and whose base measures 20cm.

 11

The perimeter of an isosceles triangle is 42cm and its base is times, each of the equal sides.

Find:


(i) The length of each side of the triangle


(ii) The area of the triangle


(iii) The height of the triangle.

 12

If the area of the equilateral triangle is cm2, find its perimeter.