Find to the three places of decimal the radius of the circle whose area is the sum of the areas of two triangles whose sides are 35, 53, 66 and 33, 56, 65 measured in centimetres.

Explanation

For the first triangle, we have

a=35 , b=53 , and c=66


`:.s= (a+b+c)/2`

`:.s= (35+53+66)/2 = 77cm`

Area of the first triangle =`sqrt(s(s−a)(s−b)(s−c))`
`:.`Area of the first triangle ` = sqrt(77(77−35)(77−53)(77−66)) =924cm^2`

...