Examples with solutions for Sum and Difference of Angles: Isosceles triangle

Exercise #1

The triangle ABC is isosceles.

C=50° ∢C=50°

Is it possible to calculate the size of angle A ∢A ?

If so, then what is it?

AAABBBCCC50°

Video Solution

Answer

Yes, 80°

Exercise #2

CE is parallel to AD.

What is the value of X given that ABC is isosceles and AB = BC?

DDDEEEBBBAAACCC2XX-103X-30

Video Solution

Answer

56.67

Exercise #3

ABC is an isosceles triangle.

DE is parallel to BC.

Angle A is equal to 3X plus 22.

Express the size of angle DEC.

AAABBBCCCDDDEEE

Video Solution

Answer

101+1.5x 101+1.5x