(i) The sides of a triangle are in the ratio

    \[7:5:3\]

and its perimeter is

    \[30\]

cm. Find the lengths of sides. (ii) If the angles of a triangle are in the ratio

    \[2:3:4\]

, find the angles.
(i) The sides of a triangle are in the ratio

    \[7:5:3\]

and its perimeter is

    \[30\]

cm. Find the lengths of sides. (ii) If the angles of a triangle are in the ratio

    \[2:3:4\]

, find the angles.

(i) It is given that

Perimeter of triangle =

    \[30\]

cm

Ratio among sides =

    \[7:5:3\]

Here the sum of ratios =

    \[7\text{ }+\text{ }5\text{ }+\text{ }3\text{ }=\text{ }15\]

We know that

Length of first side =

    \[30\text{ }\times \text{ }7/15\text{ }=\text{ }14\]

cm

Length of second side =

    \[30\text{ }\times \text{ }5/15\text{ }=\text{ }10\]

cm

Length of third side =

    \[~30\text{ }\times \text{ }3/15\text{ }=\text{ }6\]

cm

Therefore, the sides are

    \[14\]

cm,

    \[10\]

cm and

    \[6\]

cm.

(ii) We know that

Sum of all the angles of a triangle =

    \[{{180}^{0}}\]

Here the ratio among angles =

    \[~2:\text{ }3:\text{ }4\]

Sum of ratios =

    \[2\text{ }+\text{ }3\text{ }+\text{ }4\text{ }=\text{ }9\]

So we get

First angle =

    \[180\text{ }\times \text{ }2/9\text{ }=\text{ }{{40}^{0}}\]

Second angle =

    \[180\text{ }\times \text{ }3/9\text{ }=\text{ }{{60}^{0}}\]

Third angle =

    \[180\text{ }\times \text{ }4/9\text{ }=\text{ }{{80}^{0}}\]

Hence, the angles are

    \[{{40}^{0}},\text{ }{{60}^{0}}~and\text{ }{{80}^{0}}\]