Angle facts
The Maths Habit
Cut out any triangle. Tear off its three corners and put them together, points touching.
What do they make? Will it work for every triangle?
A straight line, whatever the triangle.
- Vertically opposite
- The angles across from each other where two straight lines cross.
180°Angles on a straight line
360°Angles around a point
180°Angles in a triangle
=Vertically opposite angles are equal
Find the size of angle x.
Find the size of angle x.
Find the size of angle x. Give a reason.
Reasonangles in a triangle add to 180°
Answerx =75°
Find the size of angle x. Give a reason.
Reason: angles in a triangle add to 180°
Answerx =56°
Find the size of angle x. Give a reason.
Reasonangles in a triangle add to 180°
Answerx =75°
Find the size of angle x. Give a reason.
Reasonangles in a triangle add to 180°
Answerx =36°
Find the size of angle x. Give a reason.
Reasonangles in a triangle add to 180°
Answerx =75°
Find the size of angle x. Give a reason.
straight linearound a pointtriangleisosceles
Reasonangles on a straight line add to 180°
Answerx =77°
Find the size of angle x. Give a reason.
Reasonangles in a triangle add to 180°
Answerx =75°
Find the size of angle x. Give a reason.
Reasonangles around a point add to 360°
Answerx =80°
Find the size of angle x. Give a reason.
Reasonangles in a triangle add to 180°
Answerx =75°
Find the size of angle x. Give a reason.
Reasonvertically opposite angles are equal
Answerx =128°
Three angles around a point are all equal. How big is each one?
120°Two angles make a straight line. One is four times the size of the other. Find both angles.
36° and 144°
