Drawing Triangles

Construct a triangle given two sides and one angle (SAS)

​Lesson Objectives:

​1- Construct triangles given two sides and one
angle using geometric tools.

​2- Connect triangle construction to real-life
situations.

Multiple Choice

How many triangles do you see?

• Only 2 triangles

• 4 triangles

• 8 triangles

• 12 triangles

Essential Question:
How does understanding the principles of triangle construction contribute to problem-solving and innovation in real-life contexts?

Multiple Select

Choose the construction in which a triangle can be seen within its design.

• Golden Gate Bridge

• Burj Khalifa

• Cairo Pyramids

• 1. Sydney Opera House

Essential Question:
How does understanding the principles of triangle construction contribute to problem-solving and innovation in real-life contexts?

Sample answers. ​
Architects rely on triangle construction for stable building designs.

​Engineers optimize support structures using triangle principles.

​Constructing triangles examples – SAS

EX.1 Draw the triangle ABC accurately

Practice 1

(7 minutes)

Group Work

Multiple Choice

From Practice 1, what is the length of AB

• 5 cm

• 3 cm

• 3.6 cm

• 4 cm

Practice 2

(10 minutes)

Group Work

​Hands-On Activity

Practice 3

(7 minutes)

Group Work

​A carpenter is constructing a triangular roof for a small shed. They need to determine the length of one side of the roof given the lengths of two other sides and the included angle.

• One side of the roof is 6 meters long.

• Another side of the roof is 8 meters long.

• The included angle between these two sides is 45∘

What is the length of the third side of the roof ?