Answer:
scalene
Explanation:
step 1
Find the value of y
we know that
The sum of the interior angles in a triangle must be equal to 180 degrees
In this problem
m∠A+m∠B+m∠C=180°
substitute the given values

Solve for y




step 2
Find the measure of angle B
m∠B=(y+40)°
substitute the value of y
m∠B=(15+40)=55°
step 3
Find the measure of angle C
m∠C=(3y-10)°
substitute the value of y
m∠C=(3(15)-10)=35°
The three interior angles are different
so
The three sides of the ABC triangle will also be different
therefore
The right triangle ABC is scalene