Question

justification of 75 ,105 and 135 degree angle

Answer 1

Angles can be effectively 'added' by constructing them so they share a side. This is shown in Constructing the sum of angles.

As an example, by first constructing a 30° angle and then a 45° angle, you will get a 75° angle. The table below shows some angles that can be obtained by summing simpler ones in various ways

To make Combine angles

75° 30° + 45°

105° 45° + 60°

120° 30° + 90° or 60° + 60°

135° 90° + 45°

150° 60° + 90°

Answer 2

• 75 is an acute angle

• 105 is an obtuse angle

• 135 is also an obtuse angle

ACUTE ANGLE = 0° - 90° ( EXCEPT 0° AND 90°)

OBTUSE ANGLE = 90° - 180°( EXCEPT 90° AND 180°)