Answer:
a=90⁰
b=40⁰
c=140
d=40⁰
Step-by-step explanation:
Main principle
Achieve 180⁰ on every line
a was achieved by virtue of the 90⁰ symbol
b = a+ 50⁰(90⁰+50⁰-180)
c=a+50⁰(vertically opposite angle) if you need some help,a=90⁰ (already explained above).
d=b(vertically opposite angle)
just so you understand the concept especially that of vertically opposite angles (b is vertically opposite d and therefore are equal so no calculations needed there, in the case of c, two angles when put together are opposite c so they have to be summed up and the sum is equal to angle c.
Think of it as an infinity loop the two angles facing each other are the same
OR
like the "x" symbol every angle is equal to angle direct opposite to it.
Note: Don't get confused with opposite and adjacent.
