Step-by-step explanation:
1)
The given triangle is right angled triangle having one of it's angle measured as 90°
Also , The sum of the interior angle of a triangle is 180°.
Hence, in given fig.
90° + 31° + ( 3x - 1 )° = 180
121° +3x° - 1° = 180°
120° + 3x° = 180
3x = 60°
x = 20°
So, the value of x is 20°
and the measure of the angle ( 3x - 1 ) is 3 ( 20 ) - 1 = 60-1 = 59°
2)
As from above question we know that sum of interior angle of a triangle is 180°
applying the same in this question ;
angleA + angle B + angleC = 180°
x + 5x - 8 + 3x + 44 = 180
9x + 36 = 180
9x = 180 - 36
9x = 144
x = 144/9
x = 16
So, the angle B = x = 16°
also, angle A = 5x - 8 = 5 ( 16 ) - 8
= 80 - 8
= 72°
and angle c = 3x + 44
= 3(16 ) + 44 = 48 + 44 = 92°
So, A = 72° , B = 16° and C = 92°
3) [ Refer to the attached file ]
• Right angled triangle :-
Triangle having one of it's angle measured as 90° !!
