The triangle formed by an altitude is a 30-69-90 triangle so the sides are in the ratio 2:1:√3 where √3 is the altitude. Therefore if the side of the triangle = x then altitude = √3 * x / 2 = √3x/2.
So we need to prove that 3x^2 = 4 (√3x/2)^2.
Simplifying:-
4 (√3x/2)^2 = 4 *( 3x^2/ 4) = 3x^2. This completes the proof,
She wants to read 1000 pages per week for five weeks.
So in total she wants to read 1000 * 5 = 5000 pages.
The first three weeks she read 894 pages per week.
So during the first three weeks she read a total of 894 * 3 = 2682 pages.
We want to find how many pages she must read per week for the last two weeks to reach her goal.
Goal: 5000 pages
Pages read so far: 2682
Weeks remaining: 2
To find how many pages she must read for the last two weeks we simply subtract the number of pages she read during the first 3 weeks (2682 ) by her goal ( 5000 )
5000 - 2682 = 2318
So she must read 2318 pages during the last 2 weeks.
If we want to find the amount of pages she must read per week during the last 2 weeks to reach her goal, we simply divide the amount of pages she must read during the last few weeks to reach her goal ( 2318 ) by the number of remaining weeks ( 2 )
2318 / 2 = 1159
So for the last two weeks she must average 1159 pages per week.