12 Geometry

12.01 Geometrical diagrams

12.02 Measuring angles

12.03 Parallel lines and transversals

12.04 Triangles

12.05 Angles within triangles

12.06 Quadrilaterals

12.07 Transformations and congruence

12.08 Testing for triangle congruence

12.09 Using triangle congruence

12.10 Quadrilaterals built from triangles

Stage 4

12.05 Angles within triangles

Interactive practice questions

Consider the triangle below.

A triangle with three vertices, each marked by a solid dot. The vertex at the $right$ measures $41$41 degrees marked with a yellow arc. The vertex at the $top-left$ measures $49$49 degrees marked with a blue arc; the vertex at the $bottom-left$ is unlabeled.

Is it a right-angled triangle?

Yes

A

No

B

Easy

< 1min

Consider the triangle below.

Easy

< 1min

Solve for the value of $x$x in the diagram below.

Enter each line of working as an equation.

Easy

1min

Solve for the value of $x$x in the diagram below.

Enter each line of working as an equation.

Easy

< 1min

Outcomes

MA4-17MG

classifies, describes and uses the properties of triangles and quadrilaterals, and determines congruent triangles to find unknown side lengths and angles

MA4-18MG

identifies and uses angle relationships, including those related to transversals on sets of parallel lines

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