Question

three angles of a quadrilateral are in the ratio 3 is to 5 is to 8 the mean of these angle is
80 degree find the all the four angles of the quadrilateral​

Answer 1

Answer:

Ratio of three angles = 3:5:8

Let the angles be 3x ,5x and 8x

(Given)

Mean or Average of the angles are 80 degree.

Therefore

$\frac{3x + 5x + 8x}{3} = 80 \\ \frac{16x}{3} = 80 \\ = 16x = 240 \\ = x = 15$

Three angles are

$3x = 3 \times 15 = 45 \: degree \\ 5x = 5 \times 15 = 75 \: degree \\ 8x = 8 \times 15 = 120 \: degree$

We know that sum of all angles of a quadrilateral is 360 degree

$360 - (45 + 75 + 120) \\ = 360 - 240 \\ = 120 \: degree$

Hence the angles are 45 degree,75 degree,120 degree and 120 degree