After I had practised the SMO Junior questions and after my teacher asked us to complete the P5 thinkingMath@onSponge Conquer Problem Sums, I realised that something was wrong ...
Page 149.
Based on Pythagoras' theorem, AB is 8sqrt(10). But without knowing Pythagoras' theorem, a student will calculate AB = (28 x 18)/12 = 42???Page 148.
Based on Pythagoras' theorem again, how can the three lengths of a triangle be 15, 20 and 30???Page 146.
If the lengths of the triangle are 8, 10 and 14, the area should be sqrt(s(s-8)(s-10)(s-14)) where s = (8+10+14)/2. Hence, area = 16sqrt(6). But then, how can the height be 7 if the base is 14???Page 145.
How can the hypotenuse be 8, which is shorter than the base length of 20???There are more mistakes in the book, which I am too lazy to scan and highlight in this post.
