Ask Singapore Homework?

Upload a photo of a Singapore homework and someone will email you the solution for free.



Question

secondary 3 | E Maths
One Answer Below

Anyone can contribute an answer, even non-tutors.

Answer This Question
liang liang
Liang Liang

secondary 3 chevron_right E Maths chevron_right Singapore

pls help thanks

Date Posted: 10 months ago
Views: 137

See 1 Answer

done {{ upvoteCount }} Upvotes
clear {{ downvoteCount * -1 }} Downvotes
Andrew Teoh
Andrew Teoh's answer
3 answers (Tutor Details)
1st
This is a tricky question, and there are a few things to take note of:
1. The diagram does not show it, but the model is of a square based pyramid, not a triangle. Therefore, the surface area has to include all four sides as well as the base.

2. After solving the quadratic equation, we reject the solution where x is negative, since 2x represents a real length and hence cannot be negative.

3. The model is a 1:100 scale with the real pyramid, which means 1cm becomes 1m. It is best to convert lengths from the model scale to the real scale before finding area, since a scale of 1:100 would scale 1cm^2 to 10000cm^2.

Hope this helps, and do feel free to ask any clarification questions! :)