Question

How many numbers of angles are there in the adjacent figure?

A). 10
B). 9
C). 8
D). 7

Answer 1

Hint: First name the angles that are openly visible and then take each and every line and see how many angles can be formed in precise and remember to not count the same angle twice or thrice.

Complete step-by-step answer:
Let us first of all try to name the triangles that are easily visible easily.

Each angle has 3 adjacent angles.
The combinations are,
for a⟶(a,b), (a, b+c), (a, b+c+d) and
for b⟶(a,b), (b,c), (b, c+d) and
for c⟶(b,c), (c, a+b), (c,d) and
for d⟶(c,d), (d, b+c), (d, a+b+c) and
(a+b), (c+d).
Omitting one of the terms which come twice we have
(a, b+c), (a, b+c+d), (a,b), (b, c+d), (b,c) (c, b+a), (c,d) (d, b+c),
(d, a+b+c), (a+b, c+d) .
So the total number of the pairs of adjacent angles=10.
Which clearly means that option A is the correct option here.

Note: It is necessary to omit the terms which are coming twice because they are actually the same angles, we just calculated it again and again by taking different lines in reference. So it is imperative not to cancel them.