NAMING ANGLES

Name each of the following.

Problem 1 :

The vertex of ∠1 _____

Solution :

Vertex angle :

Vertex angle is defined as the angle formed by two lines or rays that intersect at a point.

So, the vertex of ∠1 is ∠DAE.

Problem 2 :

The sides of ∠5 _____

Solution :

So, the sides of ∠5 is EB and EC.

State another name for the given angle.

Problem 3 :

∠7 _____

Solution :

∠7 is ∠AED.

Problem 4 :

∠CBE _____

Solution :

∠CBE is ∠4.

State whether the angle appears to be acute, right, obtuse, or straight.

Problem 5 :

∠2 _____

Solution :

∠2 is acute angle.

Because, acute angle that is greater than 0^º and less than 90^º is called acute angle. 

Problem 6 :

∠DEC _____

Solution :

∠DEC is Obtuse angle.

Because, Obtuse angle that is greater than 90^º and less than 180^º is called Obtuse angle.

Problem 7 :

∠AEC _____

Solution :

∠AEC is straight angle.

Because, straight angle is 180^º. 

Problem 8 :

∠CBA _____

Solution :

∠CBA is right angle.

Because, it is exactly 90^º. 

Complete :

Problem 9 :

∠DEC and _____ are adjacent angles.

Solution :

∠DEC and ∠7 or ∠5 are adjacent angles.

Problem 10 :

m ∠ 1 + m ∠ 2 = m∠ _____

Solution :

m ∠ 1 + m ∠ 2 = m∠ DAB

Problem 11 :

If m ∠ 5 = 3x – 6, and m∠ 6 = 4x + 4, then x = _____

Solution :

m  ∠ 5 = m  ∠ 6

3x - 6 = 4x + 4

3x - 4x = 4 + 6

-x = 10

x = -10

So, the value of x is -10.

Tell whether you can reach the conclusion shown based on the diagram. Write Yes or No.

Problem 12 :

DB bisects AC. _____

Solution :

DB bisects AC Yes.

Problem 13 :

m ∠DAB = 90 _____

Solution :

.m ∠DAB = 90 Yes.

Problem 14 :

E is on AC. _____

Solution :

E is on AC Yes.

Problem 15 :

AC bisects ∠DAB _____

Solution :

AC bisects ∠DAB No.