Ⲁⲛ⳽ⲱⲉⲅ:
ㅤㅤㅤ➙ ∠ a = 40°
ㅤㅤㅤ➙ ∠ b = 50°
ㅤㅤㅤ➙ ∠ c = 115 °
Ⲋⲟⳑⳙⲧⳕⲟⲛ :
∠a is formed by the intersection of two lines , so two vertically opposite angles are formed who have same measure , therefore :
ㅤㅤㅤ➙ ∠ a = 40°
∠b is formed inside a right angled triangle. As we know that the sum of all angles in a triangle is 180° , therefore we can find out the measure of ∠b using this angle sum property .
ㅤㅤㅤ➙ ∠a + ∠b + 90° = 180°
ㅤㅤㅤ➙ 40° + ∠b + 90° = 180°
ㅤㅤㅤ➙ ∠b + 130° = 180°
ㅤㅤㅤ➙ ∠b = 180° - 130°
ㅤㅤㅤ➙ ∠b = 50°
∠c is formed on a straight line by the intersection of another line , i.e the sum of both angles on a straight line is 180°
ㅤㅤㅤ➙ ∠c + 65° = 180°
ㅤㅤㅤ➙ ∠c = 180° - 65°
ㅤㅤㅤ➙ ∠c = 115°