# Pythagoras’ theorem two ways

In this lesson, students use Pythagoras’ theorem to calculate unknown side lengths in right-angled triangles after undertaking a step-by-step method of working through visual and algebraic proofs simultaneously. This will help students develop deeper connections between algebra and measurement in this context.

Year level(s) Year 9
Audience Teacher
Purpose Teaching resource
Format Web page
Teaching strategies and pedagogical approaches Classroom talks, Mathematics investigation, Worked examples, Explicit teaching
Keywords right-angled triangles, problem solving, proofs, congruency, similarity, algorithms, Maths Hub lesson plan

## Curriculum alignment

Curriculum connections Critical and creative thinking
Strand and focus Measurement
Topics Pythagoras and trigonometry, Using units of measurement, Computational thinking
AC: Mathematics (V9.0) content descriptions
AC9M9M03

Solve spatial problems, applying angle properties, scale, similarity, Pythagoras' theorem and trigonometry in right-angled triangles

Numeracy progression Understanding geometric properties (P7)
Understanding units of measurement (P10)
Proportional thinking (P7)