Question

Find the value of x in the figure​

Answer 1

50

Explanation:

let a,b

a=b being base angles.of isoceles triangle

80+a+b=180 sum of angles of triangle

80+a+a=180

2a=100

a=50

80+a+x=180 being sum of angles of triangle

50+a=100

x=50

Answer 2

25°

Explanation:

from the triangle on the left, angles BAD and BDA are equal

angles in a triangle add up to 180°

so 180 - 80 = 100 /2 = 50°

now the straight line ADC angle is 180°

so 180° - 50° = 130 ° for angle BDC

the angle for x is the same as angle DBC

for the triangle on the right angles must add up to 180°

180 - 130 = 2x

50 = 2x

25° =x