Each of the triangles are equal in base length, height, and area. Remember the formula for the area of a triangle. The area of any triangle is 1/2 times the length of the base (which, in the polygon, is the length of a side) multiplied by the height (which is the same as the apothem in regular polygon)
I'll do the math for this, it may take me a few minutes so i will update this comment with an answer in just a minute. I always get anxious when nobody replies kind of quickly as i feel it is being forgotten. So just a heads up i'm working on a answer!
Z score = (x -mean) / standard deviation.
For this problem X = 50 cm.
Z-score = (50 - 49.2) / 1.8
Z score = 0.8 / 1.8
Z score = 0.44
Look up 0.44 on a z-score table.
0.44 = 0.6700
0.67 x 100 = 67% will be 50 cm or longer.
Soooooo sorry but I only understood part a and c.
sorry
