19. In each of the following ligures, find the values of x and y

Step-by-step explanation:

→ We know that angles on a straight line add up to 180° so we can use that to work out angle x

x + 115° = 180°

⇒ Minus 115° from both sides to isolate x

x = 65°

→ We can see that there are 2 angles labelled x so we can use that to find the value of y

65° × 2 = 130°

→ We utilise the angle fact that angles in a triangle add up to 180°

130° + y = 180°

⇒ Minus 130° from both sides to isolate y

y = 50°

answer: 12

step-by-step explanation: