Ask Singapore Homework?
Upload a photo of a Singapore homework and someone will email you the solution for free.
Question
primary 5 | Maths
One Answer Below
Anyone can contribute an answer, even non-tutors.
The answer key was written as 1/2×24×24=288; 288÷2=144.
Why is it not 1/2×12×12=72?
Pls help to explain. Thank you so much.
Date Posted: 6 years ago
Views: 362
Thank you for answering. I was confused of the right angle sign on line AC. So I thought the height was line AC.
See 1 Answer
done
{{ upvoteCount }} Upvotes
clear
{{ downvoteCount * -1 }} Downvotes
Hi Yenny! It's actually very easy if you look at the triangle from another angle. Trying rotating the paper anti clockwise like in the photo. And you can see that AD = AB which is 24cm. Thus, the height of the triangle is 24 and the base, AB, is also 24. So, area of triangle ABD is 1/2 x 24 x 24. And triangle ABC is half of triangle ABD so you divide the answer by 2.
In your method of doing, the height or base of triangle ABC is AC or BC but they are both not 12cm. Nothing was written that AC or BC is half of AB. It's easy to confuse yourself on that but now you know, it should be ok. :)
In your method of doing, the height or base of triangle ABC is AC or BC but they are both not 12cm. Nothing was written that AC or BC is half of AB. It's easy to confuse yourself on that but now you know, it should be ok. :)
Date Posted:
6 years ago
I was confused of the right angle sign on AC so I thought the height is AC.
360 Tutoring Program