Well, we could try adding up odd numbers, and look to see when we reach 400. But I'm hoping to find an easier way.
First of all ... I'm not sure this will help, but let's stop and notice it anyway ...
An odd number of odd numbers (like 1, 3, 5) add up to an odd number, but
an even number of odd numbers (like 1,3,5,7) add up to an even number.
So if the sum is going to be exactly 400, then there will have to be an even
number of items in the set.
Now, let's put down an even number of odd numbers to work with,and see
what we can notice about them:
1, 3, 5, 7, 9, 11, 13, 15 .
Number of items in the set . . . 8
Sum of all the items in the set . . . 64
Hmmm. That's interesting. 64 happens to be the square of 8 .
Do you think that might be all there is to it ?
Let's check it out:
Even-numbered lists of odd numbers:
1, 3 Items = 2, Sum = 4
1, 3, 5, 7 Items = 4, Sum = 16
1, 3, 5, 7, 9, 11 Items = 6, Sum = 36
1, 3, 5, 7, 9, 11, 13, 15 . . Items = 8, Sum = 64 .
Amazing ! The sum is always the square of the number of items in the set !
For a sum of 400 ... which just happens to be the square of 20,
we just need the <em><u>first 20 consecutive odd numbers</u></em>.
I slogged through it on my calculator, and it's true.
I never knew this before. It seems to be something valuable
to keep in my tool-box (and cherish always).
By geometric and algebraic properties the angles BTC, TBC and TBC from the triangle BTC are 128°, 26° and 26°, respectively.
<h3>How to determine the angles of a triangle inscribed in a circle</h3>
According to the figure, the triangle BTC is inscribed in the circle by two points (B, C). In this question we must make use of concepts of diameter and triangles to determine all missing angles.
Since AT and BT represent the radii of the circle, then the triangle ABT is an <em>isosceles</em> triangle. By geometry we know that the sum of <em>internal</em> angles of a triangle equals 180°. Hence, the measure of the angles A and B is 64°.
The angles ATB and BTC are <em>supplmentary</em> and therefore the measure of the latter is 128°. The triangle BTC is also an <em>isosceles</em> triangle and the measure of angles TBC and TCB is 26°.
By geometric and algebraic properties the angles BTC, TBC and TBC from the triangle BTC are 128°, 26° and 26°, respectively.
To learn more on triangles, we kindly invite to check this verified question: brainly.com/question/2773823
The brain is about 1500kg when your about the age of fifteen
The next three are; 250, 1,250, and 6,250
Y=1/5x ! :) I hoped this helped ! Privately message me if you need help with anything else !!
