TERM – 2^{ND} TERM
WEEK TEN
Class: Senior Secondary School 1
Age: 15 years
Duration: 40 minutes of 5 periods each
Date:
Subject: Technical Drawing
Topic: TANGENCY
SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to
I.) Define tangency
II.) Discuss the principles of tangency
III.) Construct a tangent to a circle at a given point on the circumference.
IV.) Construct a common tangent between two unequal circles.
INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, videos from source
INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures,
INSTRUCTIONAL PROCEDURES
PERIOD 1-2
PRESENTATION |
TEACHER’S ACTIVITY |
STUDENT’S ACTIVITY |
STEP 1 INTRODUCTION |
The teacher explains the meaning of tangency. |
Students listens attentively to the teacher |
STEP 2 EXPLANATION |
Teacher guide students to construct various tangent to circle.. |
Students exhibit attentiveness and active engagement |
STEP 3 NOTE TAKING |
The teacher writes a summarized note on the board |
The students copy the note in their books |
NOTE
TANGENCY
Tangency refers to the condition where a line or curve just touches another line, curve, or surface at a single point without intersecting it. This concept is fundamental in various fields and has several principles and applications.
Point of tangency
The point of tangency is the unique point at which a given tangent line meets a geometric figure, such as a circle or plane curve. At the point of tangency, the tangent line osculates the curve but does not cross it, i.e., intersect it.
Principles:
Applications:
2.In mechanical engineering, tangency is crucial for designing components with moving parts, such as gears, cams, and rollers.
How to construct a tangent to a circle at a given point on the circumference
To construct a tangent to a circle at a given point on the circumference, follow these steps:
How to construct a common tangent between two unequal circles
To construct a common tangent between two unequal circles, follow these steps:
EVALUATION: 1. What is tangency
2i. Construct an internal tangent to two unequal circles of diameter 30 and 58 respectively, whose centres are 100 apart.
ii. Measure and state the distance between the points of tangency.(WAEC)
CLASSWORK: As in evaluation
CONCLUSION: The teacher commends the students positively