LEARNConcierge

AskQ logo

STUCK ON HOMEWORK?

ASK FOR HELP FROM OUR KIASUPARENTS.COM COMMUNITY!

Question

Answer

Points to note of the pattern 1 to 4 in the table and diagram.
1. Total number of triangle is always squared of Pattern Number
2. Shaded triangles is always ‘plus Pattern number’ more than unshaded. (Add another column for unshaded triangle in the table, you’ll see this clearer).

For pattern 28
Total triangles = 28 X 28 = 784

Unshaded + Shaded = 784

using Point 2, where shaded is always “+ pattern number” more than unshaded.

Unshaded + (Unshaded +28 ) = 784
2(Unshaded) = 784 – 28 = 756
Unshaded = 756 / 2 = 378 # for answer (c)

Shaded = 378 +28 = 406 # for answer (b)

0 Replies 0 Likes

a) 15 and 25

28 x 29 / 2 = 406 as (b)’s answer

28 x 28 = 784 as (c)’s answer

1 Reply 0 Likes

Haiz … sorry … how u get 

28×29/2? Why 29/2? 

Math not v good that’s why need step by step guide … 

your steps are similar to what is given in the answer key which blurs me. 

1 Reply 0 Likes

It is the formula for triangular numbers.
If you are passionate about mathematics, you may read more about it on https://en.wikipedia.org/wiki/Triangular_number.

This question is under patterns. 
I would recommend P6 students to know the common ones.
They might not be taught this method in school.

0 Replies 0 Likes
LEARNConcierge