Question

Section-
Q.34 Construct a triangle ABC in which BC 8 cm and 2B = 75° sum of the remaining two sides is 12 cm
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Q.35 The length of sides of triangle are in the ratio 3:4:5 and its perimeter is 144 cm Find the area of the
triangle and the height corresponding to the longest side.
[51
OR​

Answer 1

Answer:

Let the sides of triangles are 3x,4x and 5x.

And perimeter of the triangle is 144cm.

So , 3x+4x+5x=144

        12x=144

          x=12

so, the sides are triangle are 3(12)=36cm, 4(12)=48cm , 5(12)=60cm

so , the longest side is 60 cm.

Area of triangle =s(s−a)(s−b)(s−c)

here , s=72 and a=36, b=48 c=60

                           = 72(72−36)(72−48)(72−60)

                            = 72(36)(24)(12)

                             = 746496

                              = 864

So, the area of triangle is 864 cm2 and the height corresponding to longest side h=602×864=28.8cm