Question

key concept types of angles

1. draw your own example of each type of angle.

acute right obtuse straight
0 < x < x = < x < x =
in the diagram, m∠abc = 70 and m∠hfe = 90. describe each angle as acute, right, obtuse or straight. give an angle measure to support your description.

1. ∠abc
2. ∠cbd
3. ∠cfg
4. ∠cfh

lesson 1 - 4

Explanation:

Step1: Recall angle - type definitions

Acute: $0

Step2: Classify $\angle ABC$

Since $m\angle ABC=70^{\circ}$ and $0 < 70<90$, it is acute.

Step3: Classify $\angle CID$

$\angle CID$ is a straight - line angle, so it is straight ($x = 180^{\circ}$).

Step4: Classify $\angle CFG$

Since $m\angle HFE = 90^{\circ}$ and $\angle CFG$ is vertical to $\angle HFE$, $\angle CFG$ is right.

Step5: Classify $\angle CFH$

$\angle CFH=180 - 90=90^{\circ}$, so it is right.

Answer:

1. Acute
2. Straight
3. Right
4. Right