The 3rd angle is: 180-55-80 = 45 degrees
63
...a right triangle.
In any triangle exterior angle plus interior angles = 180 degrees
Each base angle is 62.5 degrees
A right angle triangle.
The missing angle measure is 100 degrees.
63
...a right triangle.
96˚all angles to a triangle equals 180˚
Since the sum of the measures of the angles in a triangle is 180°, and a right angle has a measure of 90°, it follows that the other two angles together have a measure of 90°.
The other acute angle in that triangle is 40 degrees.
77. The sum of the three angles in a triangle equal the sum of 180 degrees
two opposite interior angles.
The vertex angle of an isosceles triangle is equal to the measure of each of its base angles. Therefore, if one of the base angles measures 42 degrees, then the vertex angle also measures 42 degrees.
Let the second angle of the triangle be A. Then angle 1 = 2A : and angle 3 = 3A - 12 The internal angles of a triangle total 180° therefore :- 2A + A + (3A - 12) = 180 6A - 12 = 180 : 6A = 192 : A = 32 The angles measure 64° , 32° and 84° .
In any triangle exterior angle plus interior angles = 180 degrees
If all three angles of a triangle measure less that 90 degrees (if all three angles are acute), the triangle is an acute triangle. A triangle that has a right angle (an angle the measures exactly 90 degrees) is a right triangle. (The other 2 angles will be acute angles.) A triangle that has an angle that is greater than 90 degrees (an obtuse angle), is an obtuse triangle. (The other 2 angles will be acute angles.)