This document provides strategic intervention materials for teaching the least mastered skills in identifying the degree measure of arcs in a circle for Mathematics 10. It includes an overview, activities, assessment, and enrichment cards to help students understand central angles, minor arcs, major arcs and how to find the degree measure of each. The materials provide examples and exercises for students to practice identifying these concepts and calculating arc measures.

1. STRATEGIC INTERVENTION MATERIALS
IN MATHEMATICS 10
Department of Education
Region III
Schools Division of Zambales
GUISGUIS NATIONAL HIGH SCHOOL
Guisguis, Sta. Cruz, Zambales

2. LEAST MASTERED SKILLS
Identifying the degree measure of an
Arcs of a Circle
Sub-Tasks:
• Name and identify the central angle
of a circle.
• Name and identify the minor arc
and the major arc of a circle.
• Find the degree measure of a central
angles.
Guide
Card

3. Overview
.
Are you ready to learn more
about central angles ? Arcs
of a circle? Their
corresponding measures?
Lets go & do fun activities
to understand it!

4. Activity
Card
Yes we
can!

5. Minor arc – measure
less than 180 degrees.
- Named by using the
two endpoints of an
arc.
Major arc – measures
greater than 180
degrees.
- Named by using the
two endpoints and
another point on the
arc.
Minor Arcs Major Arcs
1.
2.
3.
4.
5.

7. DEGREE MEASURE OF AN ARC
1. The degree measure of a
minor arc is the measure of
the central angle which
intercepts the arc.
2. The degree measure of a
major arc is equal to 360
minus the measure of the
minor arc with the same
endpoints.
3. The degree measure of a
semicircle is 180°
45
30

8. Assessment
Card
In the activity you have just
done, were you able to find
the degree measure of the
central angles and arcs? I’m
sure you did! Let’s try more
fun activities!
40 45
100

9. Central
Angles
Measure Intercepted
Arc
Measure
1.
2.
3.
4.
5.
25
45
90
65

10. Enrichment
Card

11. Can You
Now
∙ Identify and name the central
angle of a circle.
• Find the degree measure of a
central angles.
• Identify and name the minor arc
and the major arc of a circle.
• Identify the degree measures of an
arc?

12. Answer
Card # 1

13. Answer
Card # 2

14. Answer
Card # 3

15. Answer
Card # 4
Central
angles
Measure Intercepted
Arc
Measure
ADB 25° AB 25°
ADC 115° AC 115°
ADE 180° AE 180°
BDC 90° BC 90°
CDE 65° CE 65°
EDF 25° EF 25°
FDG 45° FG 45°
GDH 45° GH 45°
HDA 65° HA 65°

16. Reference
Card
- Mathematics Learners Module-Grade10 (DEPED)
p. 140 – 141, 150 – 151
- New High School Mathematics, Diwa Learning System,
Inc. p. 292 – 326
- Next Century Mathematics , Mercado, Suzara & Orines
(3rd Year- Geometry), Phoenix Publishing House, Inc.
p. 121 – 125
- http://www.goggle.com

17. My Score is
________
I did great and fully
understood the lesson
51 - 75
I did good and partially
understood the lesson. I
still need to review.
26 - 50
I need to go back with the
lesson because there are
still areas I need to work
on. I will not give up.
1-25
I

19. Prepared and Submitted by:
ALMA E.BAJA
T-2
Approved:
JULITA M.VALDEZ
Principal – II