Question

If the measures of two of the angles of a triangle are 25 degrees and 60 degrees, then the third angle is _____.

• A. 95°
• B. 85°
• C. 105°
• D. 75°

Answer 1

The correct option is A

95°

Let the third angle be $x$.
We know that sum of all the interior angles of a triangle is ${180}^{\circ }$.
$\Rightarrow {25}^{\circ }+{60}^{\circ }+x={180}^{\circ }$
$\Rightarrow {85}^{\circ }+x={180}^{\circ }$
$\Rightarrow x={180}^{\circ }-{85}^{\circ }$
$\Rightarrow x={95}^{\circ }$