Which is not an appropriate classification for a triangle

right equilateral

acute scalene

obtuse isosceles

right scalene

Right equilateral is not an appropriate classification for a triangle.

Explanation:

Option a: Right equilateral

It is not possible for an equilateral triangle to be right. Because in an equilateral triangle all three angles are equal. But, in a right angled triangle not all three angles are equal.

Thus, right equilateral is not an appropriate classification for a triangle.

Option b: Acute scalene

In a scalene triangle, all three sides have different lengths. In a acute scalene triangle all three angles are acute.

Thus, Acute scalene is an appropriate classification for a triangle.

Option c: Obtuse isosceles

An isosceles triangle has two equal sides. In a obtuse isosceles triangle which has an angle more than 90° but less than 180°.

Thus, Obtuse isosceles is an appropriate classification for a triangle.

Option d: Right scalene

A scalene triangle is a triangle which has three unequal sides. A right angled triangle is a scalene triangle since it has three unequal sides.

Thus, Right isosceles is an appropriate classification for a triangle.

Hence, Right equilateral is not an appropriate classification for a triangle.

the answer is:

the correct option is the option b.

to calculate the surface area of the right cylinder, we need to use the following formula:

from the picture we know that:

so, substituting and calculting we have:

hence, we have that the correct option is the option b.

have a nice day!