Question

The angles $\angle 1,\angle 2,\angle 3,\angle 4$ are in the ratio 1 : 2: 3: 4. What is the measure of the largest angle?

• A. ${36}^{\circ }$
• B. ${72}^{\circ }$
• C. ${12}^{\circ }$
• D. ${60}^{\circ }$

Answer 1

The correct option is B

${72}^{\circ }$

Let the angles be $x,2x,3x$ and $4x$.

We know that, angles on a straight line is ${180}^{\circ }$.

$\Rightarrow x+2x+3x+4x={180}^{\circ }$

$\Rightarrow 10x={180}^{\circ }$

$\Rightarrow x={18}^{\circ }$

$\therefore$ measure of the largest angle
$=4\times {18}^{\circ }$
$={72}^{\circ }$