Answer:
measure of angle 4 is 75°
Explanation:
In triangle ALU: m∠3=180° - (55°+20°)=105°
LAP is a straight angle then: m∠3 + m∠4 = 180°
∴m∠4 = 180° - 105° = 75°
∵m∠LUA+m∠ALU= 20°+55°=75°
∴M∠4=m∠LUA+m∠ALU
∴∠4 equal the measures of the two non-adjacent interior angle and its called by the exterior angle of the triangle