Chapter 11.2, Problem 9IP

To determine

To find: Value of $x$ in each triangle.

Answer to Problem 9IP

  $x={75}^0$

Explanation of Solution

Given information:

Two angles of a triangle are ${15}^0$ and ${90}^0$

Given

Two angles of a triangle are ${15}^0$ and ${90}^0$

We know sum of angles of a triangle is ${180}^0$

Using that

We get

  $x^0+{15}^0+{90}^0={180}^0$

On solving

  $\begin{array}{l}{x}^0+{15}^0+{90}^0={180}^0\\ \Rightarrow x^0+{105}^0={180}^0\\ \Rightarrow x^0={180}^0-{105}^0\\ \Rightarrow x^0={75}^0\end{array}$

Therefore,

  $x={75}^0$

As one of the angle is ${90}^0$

So, it is an Right angled triangle