Question

The angles of a triangle are in the ratio 3:5:7. What are the angles?

• A. 36${}^{\circ }$, 60${}^{\circ }$, 84${}^{\circ }$
• B. 34${}^{\circ }$, 60${}^{\circ }$, 86${}^{\circ }$
• C. 32${}^{\circ }$, 66${}^{\circ }$, 82${}^{\circ }$
• D. 46${}^{\circ }$, 50${}^{\circ }$, 84${}^{\circ }$

Answer 1

The correct option is A

36${}^{\circ }$, 60${}^{\circ }$, 84${}^{\circ }$

Let the angles of the triangle be $3x,5xand7x.$
$3x+5x+7x={180}^{\circ }$ (Angle sum property of a triangle)
$\Rightarrow 15x={180}^{\circ }$
$\Rightarrow x={12}^{\circ }$
$\therefore$ The angles of the triangle are $3\times 12={36}^{\circ }$,
$5\times 12={60}^{\circ }$ and
$7\times 12={84}^{\circ }$