1. Find angle measures and use angles to classify triangles.
Part I: Find the missing angle measure in each triangle. Show your work. (3 points, 1 point each)
TRIANGLE 1= 50 75
TRIANGLE 2= 60 30
TRIANGLE 3= 30 45

Respuesta :

Answer:

55, Acute angled scalene triangle

90, Right angled scalene triangle

105, Obtuse angled scalene triangle

Step-by-step explanation:

Let us learn the property of a triangle.

Let a triangle be [tex]\triangle ABC[/tex].

Sum of all the three internal angles of a triangle is always equal to [tex]180^\circ[/tex].

OR

[tex]\angle A+\angle B+\angle C=180^\circ[/tex]

Given that triangles have 2 angles. Let us suppose, the third angle be [tex]x^\circ[/tex]

1. Triangle 1: two angles are [tex]50^\circ, 75^\circ[/tex]

[tex]\therefore 50^\circ+75^\circ+x=180^\circ\\\Rightarrow 125+x=180^\circ\\\Rightarrow x=55^\circ[/tex]

All the angles are less than 90 and no two angles are equal so, it is acute angle scalene triangle. (No sides equal)

2. Triangle 1: two angles are [tex]60^\circ, 30^\circ[/tex]

[tex]\therefore 60^\circ+30^\circ+x=180^\circ\\\Rightarrow 90+x=180^\circ\\\Rightarrow x=90^\circ[/tex]

One angle is 90 and not two angles are equal so, right angled scalene triangle.(No sides equal)

3. Triangle 1: two angles are [tex]30^\circ, 45^\circ[/tex]

[tex]\therefore 30^\circ+45^\circ+x=180^\circ\\\Rightarrow 75+x=180^\circ\\\Rightarrow x=105^\circ[/tex]

One angle is more than 90 and not two angles are equal so, obtuse angled scalene triangle.(No sides equal)

So, the answers are:

55, Acute angled scalene triangle

90, Right angled scalene triangle

105, Obtuse angled scalene triangle