# Lesson Notes By Weeks and Term - Senior Secondary 3

ARCHITRAVES- SEMI-CIRCULAR, LANCET, SEGMENTAL, TUDOR, PARABOLIC, ELLIPTICAL, FLAT GAUAGE ETC

TERM – 2ND TERM

WEEK THREE

Class: Senior Secondary School 3

Age: 17 years

Duration: 40 minutes of 5 periods each

Date:

Subject: Technical Drawing

Topic: ARCHITRAVES- SEMI-CIRCULAR, LANCET, SEGMENTAL, TUDOR, PARABOLIC, ELLIPTICAL, FLAT GAUAGE ETC

SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to

I.) Describe and sketch the various types of arches(Semi-circular, ecliptical, lancets)

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 guide students to sketch the various types of arches(Semi-circular, lancet, Ecliptical) Students listens attentively to the teacher and participate actively . STEP 2 NOTE TAKING The teacher writes a summarized note on the board The students copy the note in their books

NOTE

ARCHITRAVES- SEMI-CIRCULAR, LANCET, SEGMENTAL, TUDOR, PARABOLIC, ELLIPTICAL, FLAT GAUAGE ETC

Arches

An arch could be defined as a curved structure that is supported by straight sides sometimes created in wall openings suchas doors or windows of a building. In buildings, arches act as lintel because they have the ability to support the weight of blocks and other materials placed upon them.

Typical structure of an arch

A typical structure of a semi-circular arch consist in addition to the crown which is the highest point of the arch theintrados, extrados, rise, clear span, keystone, inpost,voussoir, abutment and run. See diagram below for a typical structureof a semi-circular arch.

Semi elliptical

A semi-elliptical shape refers to half of an ellipse, which is a curved shape resembling a flattened circle.

To construct a semi-elliptical shape, follow these steps:

1. Draw a horizontal line representing the major axis of the ellipse.
2. Decide the length of the minor axis, which will determine the width of the semi-ellipse.
3. Locate the foci points on the major axis. They are equidistant from the center and located outside the boundary of the ellipse.
4. Using a compass, draw the ellipse by keeping one end of the compass on one focus point and stretching the other end to the other focus point.
5. Once the ellipse is drawn, simply erase or omit the portion of the ellipse on one side of the major axis to obtain the semi-elliptical shape.
6. If necessary, refine the shape to ensure it meets the desired specifications and dimensions.

Lancet

A lancet is a pointed arch shape commonly used in architectural and structural designs, especially in Gothic architecture.

To construct a lancet arch:

1. Determine the width of the arch span and mark its endpoints.
2. Decide the height of the arch rise, typically measured from the base of the arch to its apex.
3. Using a compass, draw a circle centered at the base of the arch with a radius equal to half of the span.
4. At the top of the circle, mark the point where the apex of the arch will be.
5. Connect the endpoints of the span to the apex point using straight lines, forming a triangle.
6. Refine the triangle's shape to create a pointed arch. The arch should have steeply angled sides meeting at the apex.
7. Add any desired details or decorations to the lancet arch, such as moldings or ornamental elements.

EVALUATION: 1. What are arches.

1. Identify the arch below and draw it.

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively