Question

(C) 30
3. In a quadrilateral, three angles are in the ratio 3:3:1 and
the fourth angle is 80°, then the other angles are
(a) 100°, 100°, 80° (b) 120°, 120°, 40° (c) 100º, 1109, 70° (d) 110º, 110°, 60°
he ang​

Answer 1

Answer:

b) 120°, 120°, 40°

Step-by-step explanation:

Let us take the angles of the quadrilateral as x.

So, we get 3x°, 3x°, x°, and 80° (4th angle is given)

3x°+3x°+x°+80°=360°

7x°+80°=360°

7x°=(360-80)°

7x°=280°

x°=(280/7)°

x°=40°

Hence, we get the angles (final) as:

1st angle=(3*40)°=120°

2nd angle=(3*40)°=120°

3rd angle=(1*40)°=40°

4th angle=80° (given)

Hope this helps :)