Question

Which of the following angles do not make a triangle?

• A. $\angle A={90}^0,\angle B={60}^0,\angle C={40}^0$
• B. $\angle A={160}^0,\angle B={10}^0,\angle C={10}^0$
• C. $\angle A={100}^0,\angle B={50}^0,\angle C={30}^0$
• D. $\angle A={60}^0,\angle B={60}^0,\angle C={60}^0$

Answer 1

The correct option is A $\angle A={90}^0,\angle B={60}^0,\angle C={40}^0$

In a triangle, the sum of the three angles is ${180}^0$. In options A, C, and D,the sum of ∠A, ∠B, and ∠C is ${180}^0$.
But in option B, $\angle A+\angle B+\angle C={90}^0+{60}^0+{40}^0={190}^0$, which is not a triangle.