Answer: The measure of the vertex angle = 80°
Step-by-step explanation:
Angle sum property of triangle : The sum of the measures of the angles for any triangle is 180 degrees.
So,
[tex]3x+ 5 + 5x-25+6x-10= 180\\\\\Rightarrow\ 14x-30=180\\\\\Rightarrow\ 14x= 210\\\\\Rightarrow x=\dfrac{210}{14}=15[/tex]'
Then, vertex angle = [tex]6(15)-10=90-10= 80[/tex]
Hence, The measure of the vertex angle = 80°
