General Maths Paper Q23. c) (1 Viewer)

[Dj MuNgAs!]

does anyone know the answer to 23 part c, the question about the height of the tree? And how do u figure out the answer for it?

 

[matty_boi17]

I'm pretty sure this is wrong, but I assumed the angle opposite the right angle in the smaller triangle was 45 degrees, and then just used trig to work it out:

tan 45 = h/5m
h = tan 45 * 5
h = 5m

 

[Skeeta]

they are similar triangles

so you do a ration thing...

2:5 = 2.7: x

it ends up being about 6.75 i think

 

[ChRiS_2004]

For that question i did

h/2.7=5/2
then h= 5*2.7/2
which equals 6.75 m

 

[a_person86]

Ok, this was a tricky one.

basically with had to make the comparisons between the triangles

i did:

2/5 = 2.7/h Cross multiply

2h=13.5 divide by two
h=6.75

 

[Dj MuNgAs!]

ok tnx, cause i guessed sumfin along those lines cause i didnt know how 2 do it. I put 6.7 sumfin like dat. i just checked my calculator & i put 6.75 but i was a guess. as i just times 2.7 * 2 or sumfin like dat.

 

[dezzy]

i thought the smaller triangle was a shrinked version of the large triangle so i used my thinking cap and came up with the thesis that if i double the height of the smaller triangle and add one, i will get the height of the tree BECAUSE the measurements on the base of the little triangle was 2cm right? the base of the WHOLE triangle was 5cm...this means that by doubling the base of the small triangle and adding one, i will get 5...therefore proving my thesis!!! haha

 

[em_516]

hmm..i think i might have stuffed it then..

i did:

3/2 * 2.7 = 4.05m

because i used 3/2 as the scale factor..

 

[dave_119]

i dnt kno how u got tan!!! i got 6.75... similar figures!! 2.7/2 * 5

 

[maka]

em i got the same

used the englarment ratio thinga nd got 4.05

 

[em_516]

em i got the same

used the englarment ratio thinga nd got 4.05

haha..and we're wrong..damn stupid mistakes! it should have been 5/2..grrr..

 

[will_17]

I found out the percentage at which 2 inceased to 3 adn then used that percentage to increase the hieght of the small triangle and it ended up being 6.75 or somehting. I winged that question...

 

[IP_freely]

its 6.75 an if u still cant get it go to the Yr 11 New century maths book it will tell u how to work it out

 

[LadyBec]

i did it wrong i think *shrugs*

 

[Dynamix]

calculate the angle in the triangle opposite to the tree using tan and then work out using tan again the heifght of the tree by substituting in tan(angle) =h/base length, then go h=base length tan(angle). Easy, although i cant remember the values

 

[pussy_cat]

I figured out the angle using the small triangle then used the angle and one side, and cos to get the height, dont think i got the right answer, but gotta get marks for tryin lol

 

[maka]

em i was just gonna say after lookin over the paper the easiest question of the paper and i drop a mark on it it was 5/2 with a rough answer on 6 like ppl have been sayin