Count number of Triangles
Type-1
➯ Counting triangles with in Square, Rectangle, Quadrilateral.
Find the number of triangles in the above figures.
Figure – 1 : Number of triangles = 8
Hint: Here having total two diagonals and having four blocs. So formula for that 2 x 4 = 8 number of triangles.
Figure – 2: Number of triangles= 16
Hint: Here having total two diagonals and having 8 blocs. So formula for that 2 x 8 = 16 number of triangles.
Figure – 3: Number of triangles = 18
Hint: Here each square having 8 no. of triangles and combine squares having 2 no. of triangles. So total number of triangles (2×4) + (2×4) + 2 = 18.
Figure – 4: Number of triangles = 28
Hint: Here each square having 8 no. of triangles and combine squares having 4 no. of triangles. So total number of triangles (2×4) + (2×4) + (2×4) + 2+2 = 28.
Type-2
➯ Counting triangles with the Triangle having number of bisects with vertex.
Count the number of possible triangles from the following figures.
Formula : Here number of parts be ”n” then possible triangles is n(n+1)/2
Figure – 5: Number of possible triangles = 1
Figure – 6: Number of possible triangles = 3
Figure – 7: Number of possible triangles = 4(4+1)/2 = 10
Figure – 8: Number of possible triangles = 5(5+1)/2 = 15
Type – 3
Counting triangles with the Triangle having number of bisects with vertex and horizontal lines.
Count the number of triangles in the given figures.
Figure – 9: Triangle counting in Fig-9 = 2
Figure – 10: Triangle counting in Fig-10 = 6
Figure – 11: Triangle counting in Fig-11 = 30
Figure – 12: Triangle counting in Fig-12 = 45