Here is a trapezoid. On one of the heights like AE imagine that you cut along the height. You now have a triangle but you then can go attach this to the other side of the parallelogram and there you have a rectangle.
Here show where you cut the triangle off
then you can simply put the triangle you cut off on the other side of the trapezoid to make a rectangle. Then you may multiply the base length by the height of the Rectangle to get the area[top eraser a great example of a Parallelogram!]
How to solve a problem like this
A=150mm2<-REMEMBER TO SQUARE THE AREA
Finding the Areas of Circles
Lets solve one.
So your Radius is 10ft and use 3.14 for pi
A=314ft2< Remember to square the answer
Have to congruent which means they are the same bases. the other sides are rectangles
is a polyhedron, have only one base other sides are triangles
solid with 2 congruent circular bases that lie parallel planes
The formula and how to solve for a pyrimid
B is the base of the pyramid which means you must use the formula for that shape
P is the length of one of the sides in the base
l= length or called slant height from the side of the base to the top vertex
Example: Base Rectangle 15in by 12in l= 34in P=12in
Finding the surface area of a Cone
Lets do one
Radius= 5 feet Height= 12 feet
With this problem you need to use the pythagorean theorem to find the slant height.
Which is A2+B2=C2
169=c2 But now you must square root 169
SA=282.2 Feet^2 Remember to square your answer
Finding the volume of a cylinder
Radius= 6cm Height= 3cm
so the area of the circle you do
Area=3.14*6^2 = 113.04 then..
113.04*3= 339.12cm3 REMEMBER TO CUBE THE ANSWERS AND ADD A LABEL!
Formula for a Pyramid: V=1/3Bh
Lets do one
length1 15in length2= 15in slant height=16in
so first you want to divide the length 1 by 2 to get 7.5 this is one base of a triangle You then use the pythagorean theorem to get the length from the middle to the top vertex this is... 17.7in you then plug in the formula for the base A=bh= 225in^2 then multiply by 1/3 and then multiply by 17.7 to get you answer of 1327.5in^3
Volume of a Cone
The base is the area of a circle pi*r2
Then you use the height of the center of the circle to the top of the cone
Area of a Trapezoid=A=.5(b1=b2)h
Area of a Circle=3.14*r2
Surface area of a Prism=SA=2b=Ph or just find the area of all the shapes and add
Surface area of a Cylinder=SA=2B=Ch or just do the same as in the Prism ex.
Surface area of a Pyramid=SA=B=.5Pl
Surface area of a Cone=SA=3.148r2=3.14*r*l
Volume of a Prism=V=Bh
Volume of a Cylinder=Bh but with a circle base
Volume of a Pyramid=V=1/3Bh
Volume of a Cone=V=1/3Bh no slant height
Volume of a Sphere=V=4/3*3.14r3
Surface area of a Sphere= SA=3.14*4*r2