Find the number in place of ?
From the 1st picture (9)2-(4)2= 81-16 = 65
From the 2nd picture (8)2-(6)2= 64-36 = 28
From the 3rd picture (7)2-(2)2= 49-4 = 45
Therefore the required number is 45
How many triangles can be formed from the given picture ?
From the picture, the following triangles can be formed.
AIC, AIB, ADC, AIH, ACH, ADG,BIC, CID,CHD, DIJ, DIH, JIH, DAH, ADG, HCE, HKD, HKJ, HED, HKG, HEG, JKD, DKE, DGE, EKF, EKG, EHG, FKG, GDH.
Therefore 28 triangles can be formed from the given picture.