Question

An exterior angle of a triangle is 120^o and one of the interior opposite angles is 40^o. Find the
other two angles of triangle.

Answer 1

Answer:

let ABC be a triangle.

by exterior angle property of Δ

<ACD = <A + <B

120° = 40° + y

y = 120° - 40°

y = 80°

by angle sum property of triangle

<A + <B + <ACB = 180°

40° + 80° + x = 180°

x = 180° - 120°

x = 60°

hence, the other angles of Δ is 80° and 60°