Question

Find the value of each variable, line l is tangent.

Answer 1

b=40 c=40 a=80 and d=100

Explanation:

B=40

B=c

C=40

40+40+d=180

D=180-80

D=100

c=1/2a

40=1/2a

A=80

Answer 2

This is the concept of geometry, we are required to find the values of angle a,b,c,d;
Given that the triangles are by line intersecting two parallel lines, therefore we can conclude that both triangles are similar;
thus;
angle b=40° ⇒alternate angles
angle b= angle c=40° ⇒base angles of isosceles triangles are equal;
angle d=180-(40+40)=180-80=100°
angle a=360-80=240°