This is the third time this question has been answered since yesterday, each time posted by students
with a different name. Are you just switching names?
https://www.jiskha.com/questions/1825627/the-sides-of-the-pentagon-are-quadrupled-so-they-are-now-times-as-large-this-means
I know this question has been answered, but I still don't understand. Please help.
The sides of the pentagon are quadrupled, so they are now __ times as large. This means the area is now __ times as large. This is equivalent to an increase of __%.
3 answers
I don't understand the solution, can you help me?
Ok
The pentagon is made up of 5 equal isosceles triangles with a central angle of 72°, right?
Each base angle = 52°
if we let the base = 2, then the height will be:
tan52 = h/1
h = tan52
and the area of one triangle = (1/2)(2)tan52° = tan52
area of whole pentagon = 5tan52
so we are quadrupling the base, so the base is now 8
and the height is 4tan52°
area of whole pentagon = (1/2)(8)20tan52 = 80tan52
how many times larger is 80tan52 than 5tan52 ????
80tan52/(5tan52) = 16
The pentagon is made up of 5 equal isosceles triangles with a central angle of 72°, right?
Each base angle = 52°
if we let the base = 2, then the height will be:
tan52 = h/1
h = tan52
and the area of one triangle = (1/2)(2)tan52° = tan52
area of whole pentagon = 5tan52
so we are quadrupling the base, so the base is now 8
and the height is 4tan52°
area of whole pentagon = (1/2)(8)20tan52 = 80tan52
how many times larger is 80tan52 than 5tan52 ????
80tan52/(5tan52) = 16
3 answers