Question

Give the missing angle​

Answer 1

a = 60°

b = 115°

c = 65°

Explanation:

Alternate Interior Angles Theorem

If a line intersects a set of parallel lines in the same plane at two distinct points, the alternate interior angles that are formed are congruent (same).

Therefore, a = 60° and c = 65°

Angles on a straight line sum to 180°

⇒ b + 65° = 180°

Subtracting 65° from both sides:

⇒ b + 65° - 65° = 180° - 65°

⇒ b = 115°

Answer 2

• 60°, 115°, 65°

Explanation:

Angles a and 60°, also c and 65° are alternate interior angles and therefore are equal:

• a = 60°
• c = 65°

Angles b and 65° form a linear pair, so they sum to 180°

• b + 65° = 180°
• b = 180° - 65°
• b = 115°