Question

In ∆ABC, A=40° and B=60°, then the triangle is is

Answer 1

$Given , In \: \triangle ABC , \angle A = 40\degree,\\and\: \angle B = 60\degree$

/* By Angle Sum Property */

$\angle A + \angle B + \angle C = 180\degree$

$\implies 40\degree + 60\degree + \angle C = 180\degree$

$\implies 100\degree + \angle C = 180\degree$

$\implies \angle C = 180\degree - 100 \degree$

$\implies \angle C = 80\degree$

$\pink {( All \: three \: angles \: less \:than \: 90\degree )}$

$\therefore \triangle ABC \: is \:a \\ \underline { \blue { Acute \: angle \: triangle }}$

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Answer 2

Given that ,

The two angles of triangle ΔABC are 40° and 60°

We know that ,

The sum of all angles of triangle is 180

Thus ,

40 + 60 + C = 180

100 + C = 180

C = 80

Since , each angle is less than 90°

$\therefore \sf \underline{The \: triangle \: is \: acute \: angled \: triangle }$