Question

In a right triangle the two acute angles are in the ratio 4 : 5. The acute angles are :

• A. 50 : 40
• B. 40 : 50
• C. 45 : 55
• D. 30 : 60

Answer 1

The correct option is B 40 : 50

Let the angles be $4x$ and $5x$

Now their sum is ${90}^{\circ }$

$4x+5x={90}^{\circ }\Rightarrow 9x={90}^{\circ }\Rightarrow x={10}^{\circ }$

So the angles are

$4\times {10}^{\circ }={40}^{\circ }5\times {10}^{\circ }={50}^{\circ }$