Angles (Math 5)

Angles (Math 5)

Chapter 6 (pages 79-84)

Sum of angles in a triangle

Let us look at how can we find the sum of angles in a triangle.

The sum of angles in a triangle is 180^o.

∠a + ∠b + ∠c = 180^o.

In Triangle ABC, ∠CBA=46^o and ∠BAC=93^o. Find ∠ACB. (The figure is not drawn to scale.)

Triangle STU is an equilateral triangle. Find ∠s. (The figure is not drawn to scale.)

Triangle DEF is an isosceles triangle. ∠DEF=110^o. Find ∠EFD. (The figure is not drawn to scale.)

The figure below is made up of Triangle WYX and Triangle WZY. ∠XWY=52^o and ∠YXW is a right angle. Find ∠y and ∠z. (The figure is not drawn to scale.)

The figure below is made up of Triangle ABC and Triangle CDE. AD and EB are straight lines that cross each other at the point C. Find ∠q. (The figure is not drawn to scale.)

The figure below is made up of Triangle DEI, Triangle IEH and Triangle EFG. DG and FH are straight lines that cross each other at the point E. Find ∠x. (The figure is not drawn to scale.)

page 83

page 84