1. Recapping: Congruent triangles
Shown below are five triangles that are not drawn accurately.
Four of the triangles are congruent.
Which is the odd one out?

2. Angles of Elevation and Depression
Learning Objective: Draw and measure line segments and angles in geometric figures, including interpreting scale drawings.
From the top of a lighthouse the angle of depression to a buoy out at sea is 23°.
Using a scale drawing of 1 cm : 4 m, make a scale drawing and use it to find the distance of the buoy to the base of the lighthouse.

3. Angles of Elevation and Depression
Learning Objective: Draw and measure line segments and angles in geometric figures, including interpreting scale drawings.
From a point A on the ground, which is 50 m from the base of a tree the angle of elevation of the top of the tree is 30°.
Using a scale of 1cm = 5 cm, make a scale drawing to find the height of the tree.

4. Angles of Elevation and Depression
Learning Objective: Draw and measure line segments and angles in geometric figures, including interpreting scale drawings.
From a hot air balloon the angle of depression of a blue box on the ground is x°.
Use a scale drawing to find the angle of depression.