Study the pattern.

1. Find the total number of white and grey triangles in Figure 250.
2. Find the percentage of grey triangles in Figure 250. 

(a)
Total number of triangles.
Figure 1: 1 = 1 x 1
Figure 2: 4 = 2 x 2
Figure 3: 9 = 3 x 3
Figure 4: 16 = 4 x 4
Figure 5: 25 = 5 x 5

Formula:
Total number of triangles = Figure number x figure number

Total number of grey and white triangles for Figure 250
= 250 x 250
= 62500

(b)
Difference in the number of white and grey triangles.
Figure 1: 1 - 0 = 1
Figure 2: 3 - 1 = 2
Figure 3: 6 - 3 = 3
Figure 4: 10 - 6 = 4

Formula:
Difference in the number of white and grey triangles = Figure number

Number of white triangles = 1 u
Number of grey triangles = 1 u + Figure Number

Total number of triangles
= 250 x 250
= 62500

1 u + 1 u + 250 = 62500
2 u = 62500 - 250
2 u = 62250

1 u = 62250 ÷ 2 = 31125

Number of grey triangles
= 1 u + 250
= 31125 + 250
= 31375

Percentage of grey triangles in Figure 250
= ³¹³⁷⁵₆₂₅₀₀ x 100%
= 50.2%

Answer(s): (a) 62500; (b) 50.2%