Check the length of all the sides and measures of angles.

Think of a name for such a length.

circles are round in shape/

Recall the definition of a altitude.

Take the median as x and then find the value of line segment in x and solve the equation.

Angle should be 90 degree.

Check the lines joining the vertices.

an altitude of a triangle is a line segment through a vertex and perpendicular to a line containing the base.

Triangle has three sides and three corners.