Question

Jenna has a habit of drawing some random shapes whenever she feels bored.
She draws a shape that looks like the one below.
Help Jenna find the number of triangles in the given figure.

• A. 28
• B. 30
• C. 12
• D. 32

Answer 1

The correct option is A 28

Let's first label the figure:

• Number of simple triangles:

AJG, GJK, GKD, DKH, HKJ, HJB, BJF, FJI, FIC, CIE, EIJ, EJA
= 12

• Number of triangles formed by joining 2 simple triangles:

JGD, GDH, DHJ, HJG, JFC, FCE, CEJ, EJF
= 8

• Number of triangles formed by joining 3 simple triangles:

AJD, DJB, BJC, CJA
= 4

• Number of triangles formed by joining 6 simple triangles:

ADB, DBC, BCA, CAD
= 4

Total number of triangles = 12 + 8 + 4 + 4 = 28

Thus, there are 28 triangles in the given figure.