Question

One angle of an isosceles triangle measures 120°. What measures are possible for the other two angles? Choose all that apply.

10°
30°
80°
50°

Answer 1

b) 30°

Additional information:-

• One angle (x) = 30°
• Both angles (2x) = 60°

Explanation:

We know that,

→ The other two angles of the isosceles triangles are equal.

Formula we use,

→ <A + <B + <C = 180°

Forming the equation,

→ 120° + x + x = 180°

Now the value of x will be,

→ 120° + x + x = 180°

→ 120° + 2x = 180°

→ 2x = 180° - 120°

→ 2x = 60°

→ x = 60°/2

→ [ x = 30° ]

Hence, option (b) is correct.