The sides of a triangle are in the ratio 8 : 9 : 10 and its perimeter is 270 cm. What is its area?
Answer & explanation
Correct answer: option 3
We have,
The sides of a triangle are in the ratio 8 : 9 : 10
Its perimeter = 270 cm
so the semi perimeter will be = \(\frac{270}{2}\) = 135
According to the question,
Perimeter is the sum of all the sides of the figure.
Area of a triangle = \(\sqrt {s(s-a)(s-b)(s-c) }\)
Let the sides are = 8x , 9x and 10x
Now, 8x + 9x + 10x = 270
27x = 270
x = 10
So the sides are = 8x = 80
9x = 90
and 10x = 100
Area = \(\sqrt {135(135-80)(135-90)(135-100) }\)
= \(\sqrt {135(55)(45)(35) }\)
= $225\sqrt{77}cm^2$