Lesson #1 title: PART 1 = CONSTRUCTING triangles in the 1st quadrant of a Cartesian plane
Date:
THROUGH-LINE: Creation-enjoying
Creation is enjoyed when SIDE lengths and/or INTERIOR  are used to classify triangles and regular & irregular polygons.
OUTCOMES:
1. Construct triangles in different orientations in the first quadrant of a Cartesian plane, and
identify the points used to produce them.
2. Identify triangles according to their sides and/or their interior angles (e.g., SIDES = equilateral Δ,
isosceles Δ, scalene Δ; INTERIOR  = acute Δ, right Δ, obtuse Δ)
MATERIAL NEEDED: highlighters, pencil, blue pen, double scale protractor, ruler, 1 cm grid paper.
Example #1: (obtained from MsT’s head 2016)
On the grid, DRAW these 3  and label the length of each side (use ‘ticks’ to indicate equal
line segments) and label each vertex with a different alphabetical letter (spread out your
angles on the grid)
a) An acute angle that is 60o AND each line segment is 3 cm.
b) A right angle AND each line segment is 3 cm.
c) An obtuse angle that is 120o AND one line segment is 3 cm and the other line
segment is 5 cm.
TRANSFORM each into a Δ by joining the ‘outermost vertices’ in each angle.
1. Label the degrees of each angle.
2. Label the length of each side (use ‘ticks’ to indicate equal line segments).
3. Label the ordered pairs of each vertex.
REPLICATE each triangle in different orientations on the grid, and show that the
two are congruent.
What type of triangles did you construct?
The acute angle became
1.
2.
The right angle became
1.
2.
The obtuse angle became
1.
2.