Question

Two angles of a triangle are ${54}^o$ & ${72}^o$. Find the ratio of third angle to the sum of first two angles.

Answer 1

Given two angles are $54$ and $72$

We know that sum of angles of a triangle is $180$

Let the third angle be $\theta$

$54+72+\theta =180$

$\theta =180-126$

$=54°$

Sum of first two angles$=54+72$

$=126°$

Ratio of third angle to the sum of first two angles$=\frac{54}{126}=\frac{18}{42}$

$=\frac{3}{7}$