If the length of only one side is known, it is not possible to determine whether or not the triangle is right angled.
never
yes
Yes
If you have one right angle then you can use the Pythagorean theorem. A^2 (meaning A squared)+ b^2=c^2
in a right trianlge the tangent is the ratio of Opposite/Adjacentcosine is Adjacent/Hypotenusesine is Opposite/Hypotenuse
For a right angle triangle the square looking shape in the corner represents 90 degrees
180 degrees
No, they cannot.
88
A isosceles triangle
8
The sum of the angles in a triangle is 180 degrees.