So, I have a triangular based pyramid made of 3 congruent isosceles triangles, they are 9 cm by 11 cm by 9 cm, and it's 45 degree angles. What is the volume and formula?

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You need to calculate the slant height of the pyramid for the formula of the lateral area. You should find a value of ** (1/2)*SQRT(203) **or about 7.1239 cm

You need to calculate the altitude (height) of the pyramid from the apex (summit) to the center of the base triangle (center of inscribed circle, barycenter, orthocenter). The hypotenuse of such triangle is the slant height. One leg is the altitude (to be found), **the measure of the second leg is (1/3) the altitude** **of the equilateral triangle** that forms the base. You should find (1/3) m MH= (1/3)* **(11/2)*SQRT(3)**

1. Calculate the area of the base (use a formula for the equilateral triangle or the general formula for a triangle: you have its height MH ).

2. Lateral area = 3 times the area of triangle Triangle ECD (in yellow above).

3. Total area = area of base + lateral area.

4. Volume= (1/3)(Area of base)* (height of pyramid)

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Posted on Mar 30, 2014

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Posted on Jan 02, 2017

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SOURCE: finding the length of a triangle

might try

(54tan)/45

I don't have a calc that will do it or I would try it and see.

Posted on Aug 01, 2008

SOURCE: the old manual used to come with instructions to

Hi - welcome to Fixya.

You're refering to Trigonometry or 'Trig'. The basic formula is easily remembered as SOH-CAH-TOA:

**SOH: Sine of an angle is Opposite over Hypotenuse ****

**CAH: Cosine of an angle is Adjacent over Hypotenuse ****

**TOA: Tangent of an angle is Opposite over Adjacent ****

** See attached image below

I can't tell you which buttons to press on your calculator, but you can download a new manual from here:

http://www.retrevo.com/support/TI-TI-30Xa-Calculators-manual/id/421ci270/t/2/

The download page will open in a new Browser window. Scroll down a little and click on "Download the Manual". On the next page, scroll to the bottom and enter the 5-digit security code in the box then click "Download" now. You can then save the file to your PC and/or print it for future reference. You __don't__ need to enter your email address to download the manual. If you can't open the manual you may also need to download the latest version of Adobe Reader:

http://get.adobe.com/reader/

If you have any trouble downloading the instruction manual or you have any further maths questions, please post back and I will be happy to assist you.

Regards,

BElectric.

Posted on Nov 23, 2010

SOURCE: The base of a cylinder has a diameter of 6.2 cm.

When you have to deal with problems of this sort, you usually are given recipes or mathematical formulas which you apply to find the result. It so happens that for the volumes of cylinders, the formula to use is

Volume = Area of the base times the height=Ab*h

If the cylinder is circular, then the area of the base is that of a disk, Ab=PI*r^2`where r is the radius.

In your case, you are given the diameter (twice the radius) and the height.

Volume =PI*h*(6.2/2)^2, the unit being cm^2

To type in the value of PI, press [2nd] [^] (the latter is key under CLEAR, and above the division sign.

To raise a number to power 2 (to square it), use the key marked x with a superscript 2, or x with a raised 2.

After you have typed in all necessary ingredients in the formula, press the [ENTER] key and the calculator will give you the result.

Now, it is your turn to do some mathematics.

Posted on Jun 16, 2011

SOURCE: given a length of 30 cm on the x axis and a length

Yes, there is shortcut because this is right triangle, so you can use Pythagorean theorem (see picture).

- Length of hypotenuse is square root of sum of squares of lengths of other two sides of triangle, which is equal to square root of 30^2+10^2=31.6 cm.
- Sin(a)=longer cathetus/hypotenuse=0.949 so a=arcsin(0.949)=71.6 degrees
- Finally b=90-a=18.4 degrees.

If this was helpful please rate 4 thumbs :)

Posted on Sep 05, 2011

SOURCE: calculate in degrees, the angle subtended at the

About 146 and a half degrees.

If this is homework, make sure to show your work.

Posted on Oct 22, 2013

Testimonial: *"thank you"*

Three congruent angles means it is an equilateral triangle, so by definition it has 3 congruent sides. Or, by the Sine Rule of triangles

a/sinA = b/sinB = c/sinC

and since A = B = C (given) then a = b = c.

.

a/sinA = b/sinB = c/sinC

and since A = B = C (given) then a = b = c.

.

Apr 08, 2016 | Computers & Internet

A triangle with two sides of equal length is an isosceles triangle. The side that is different from the other two is usually called the base, and the two angles at the base are equal.

Aug 01, 2014 | The Learning Company Achieve! Math &...

I assume you mean a square base.

2.0833 litres.

If this is homework, be sure to show your work.

2.0833 litres.

If this is homework, be sure to show your work.

Feb 27, 2014 | Office Equipment & Supplies

2.0833 litres.

If this is homework, be sure to show your work.

If this is homework, be sure to show your work.

Feb 27, 2014 | Office Equipment & Supplies

You need 5 isosceles triangles with a base of 30 mm. To get the height of the triangles (perpendicular to the 30 mm bases) you need to calculate the apothem of the pentagon (assumed to be regular).

If you cut the pyramid by a plane passing through its apex, the center of the base-pentagon,and the midpoint of one side, the plane figure created by the three points (apex, center, and midpoint) is a right triangle. The legs are the apothem, and the altitude of the pyramid. The hypotenuse is the slant height of the pyramid, and is thus the height of the triangles in the development. pyramid (60 mm) form.

Use the Pythagorean Theorem to find that slant height.

**s^2=a^2+h^2**.

If you cut the pyramid by a plane passing through its apex, the center of the base-pentagon,and the midpoint of one side, the plane figure created by the three points (apex, center, and midpoint) is a right triangle. The legs are the apothem, and the altitude of the pyramid. The hypotenuse is the slant height of the pyramid, and is thus the height of the triangles in the development. pyramid (60 mm) form.

Use the Pythagorean Theorem to find that slant height.

Nov 11, 2013 | Computers & Internet

A pyramid is made of triangles, and the number of triangles for a particular pyramid base. For a square base pyramid - 4 triangles; pentagonal base - 5 triangles

Sep 26, 2011 | Riverdeep Mighty Math Cosmic Geometry...

In right triangle we are making 90 degree angle triangle, we can have problem for finding hypotenuse or finding sin or cos values of the side of the triangle.
For ex,Find out the hypotenuse,sin and cos value of the right triangle with base 4 cm and perpendicular 3 cm
Solution:Hypotenuse = SQRT(4^2 + 3^2)
=SQRT(4*4 + 3*3)
=SQRT(16+9)=SQRT(25)=5 cm
For right triangle,
sin(x)=3/5=0.6
cos(x)=4/5 =0.8

Jul 16, 2010 | Super Tutor Trigonometry (ESDTRIG) for PC

Assuming you want the triangle segmented, first, insert an Isosceles Triangle from the Basic Shapes list on the home screen for the top of the pyramid. Then, for the lower sections, use the Flowchart:Manual Operation symbol and flip it upside down. You'll need to play with the sizes a bit to get the look you want, but it shouldn't take too long.

Jul 14, 2009 | Microsoft Office PowerPoint 2007 Upgrade...

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