Angles

If angle a is 70 and angle c is 110, what must be angle b? What kind of a triangle is triangle BCD?

• 70, isosceles

• 40, isosceles

• 110, equilateral

• 40, equilateral

If angle a =120 degrees, What is the measure of angle b .

• 150

• 120

• 60

• 110

If angle a=70, angle b =55 and angle c = 80,

what are the values for angles d, e and f? Show how you arrive at your answer.

Answer explanation

considering the isosceles triangle,

e = 180 -70-70 = 40 ( base angles are same = 70)

< d = 180 - < b - < c = 180- 55-80 = 45

<f = 180- <b- <e = 85

If b = 30 degress, What are the values of a and c?

• a= 150

  c= 120

• a= 150, c = 150

• a=130

  c=150

• a=120

  b = 150

A quadrilateral has 4 angles a, b, c and d. If the sum of angles a and c is 130, suggest values for angles b and d.

Express a in terms of b