Question

On a piece of paper, use a protractor to construct a triangle with angle measures of 60° and 80°. Select from the drop-down menu to correctly classify the triangle. A triangle with angle measures of 60° and 80° is______triangle.
A. acute
B. obtuse
C. right angle

Answer 1

The sum of interior angles of a triangle must add up to 180 degrees

if the triangle has an angle that is greater than 90 degrees, then it is considered obtuse

if the triangle has an angle that is 90 degrees, then it is considered right

if all angles are less than 90, then it is acute

find the missing angle "x"

180=60+80+x

is angle x less than, greater, or equal to 90 degrees?

Answer 2

The answer to your question is A. This is because an acute angle is less than 90 degrees. Also, the triangle angle sum theorem says that the measures of the angles in a triangle must add to be 180. So 60+80=140. 180-140=40. Therefore all the triangles angles are less than 90 degrees so the triangle is acute.