counting figures for ntse

Question 1:

How Many Triangles are there in the Given Figure?

Answer:

18

Solution:

Number of triangles=4*2 + 4*2 + 2= 8+8+2=18

Question 2:

How Many Triangles are there in the Given Figure?

Answer:

28

Solution:

Number of triangles=4*2+4*2+4*2+2+2=8+8+8+4=28

Question 3:

How Many Triangles are there in the Given Figure?

Answer:

2

Solution:

Number of triangles=2=ABC and ADE

Question 4:

How Many Triangles are there in the Given Figure?

Answer:

6

Solution:

Number of blocks made by vertical line(x)=2=ABF and AFC
and Number of blocks made by horizontal line(y)=2=BCED and ADE
Therefore,
Number of triangles=[x*y(x+1)]/2
=[2*2(2+1)]/2
=[4(3)]/2
=12/2
=6

Question 5:

How Many Triangles are there in the Given Figure?

Answer:

30

Solution:

Number of blocks made by vertical line(x)=4=ABC,ACD,ADE and AEF
and Number of blocks made by horizontal line(y)=3=HBFJ, GHJI and AGI
Therefore,
Number of triangles=[x*y(x+1)]/2
=[4*3(4+1)]/2
=[12(5)]/2
=60/2
=30