SOLUTION: 1. The height of a triangle is 2 m more than twice the length of the base. The area of the triangle is 42 m2. Find the height of the triangle. 2.a2 – 3a = 28 3.(a &#8722

Algebra ->  Customizable Word Problem Solvers  -> Geometry -> SOLUTION: 1. The height of a triangle is 2 m more than twice the length of the base. The area of the triangle is 42 m2. Find the height of the triangle. 2.a2 – 3a = 28 3.(a &#8722      Log On

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Question 645496: 1. The height of a triangle is 2 m more than twice the length of the base. The area of the triangle is 42 m2. Find the height of the triangle.

2.a2 – 3a = 28

3.(a − 4)(a + 6) = −16

4. 5y(y + 6) = 4(y + 6)

Found 2 solutions by solver91311, MathLover1:
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


Let represent the measure of the base of the triangle. Then the measure of the height must be . Since we know that the area of a triangle is the measure of the base times the measure of the height divided by 2, we can write:



Which is to say:



or



Solve the factorable quadratic for the positive root (discard the negative root because we are looking for a measure of length for which negative values are absurd). Once you have a value for , calculate

John

My calculator said it, I believe it, that settles it
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Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!
1. The height of a triangle h is 2m more than twice the length of the base a.
=>... h=2a%2B2m...=>..h-2m=2a =>..a=%28h-2m%29%2F2
The area of the triangle A is A=42m%5E2.
Find the height of the triangle.
A=%281%2F2%29a%2Ah
42m%5E2=%281%2F2%29a%2Ah........replace a with %28h-2m%29%2F2
42m%5E2=%281%2F2%29%28h-2m%29%2F2%2Ah...solve for h
42m%5E2=%28%28h-2m%29%2F4%29%2Ah
42m%5E2=%28%28h-2m%29h%2F4%29
42m%5E2=%28%28h%5E2-2hm%29%2F4%29
42m%5E2%2A4=h%5E2-2hm
168m%5E2=h%5E2-2hm
0=h%5E2-2hm-168m%5E2...or
h%5E2-2hm-168m%5E2=0....use quadratic formula to find h
h+=+%28-%28-2%29+%2B-+sqrt%28+%28-2%29%5E2-4%2A1%2A%28-168%29+%29%29%2F%282%2A1%29+
h+=+%282+%2B-+sqrt%284%2B672+%29%29%2F2+
h+=+%282+%2B-+sqrt%28676+%29%29%2F2+
h+=+%282+%2B-+26%29%2F2+
solution: we need only positive solution since the height cannot be negative
h+=+%282+%2B+26%29%2F2+
h+=+28%2F2+
highlight%28h+=+14m+%29
now find the length of the base a
a=%28h-2m%29%2F2
a=%2814m-2m%29%2F2
a=%2812m%29%2F2
highlight%28a=6m%29

2.
a%5E2-3a+=+28
a%5E2-3a+-28=0
a+=+%28-%28-3%29+%2B-+sqrt%28+%28-3%29%5E2-4%2A1%2A%28-28%29+%29%29%2F%282%2A1%29+
a+=+%283+%2B-+sqrt%289%2B112%29%29%2F2+
a+=+%283+%2B-+sqrt%28121%29%29%2F2+
a+=+%283+%2B-+11%29%2F2+
solutions:
a+=+%283+%2B11%29%2F2+
a+=+17%2F2+
highlight%28a+=+7%29+
or
a+=+%283+-11%29%2F2+
a+=+-8%2F2+
highlight%28a+=+-4+%29



3.
%28a+-4%29%28a+%2B+6%29+=-16

a%5E2%2B6a+-4a+-24+=-16
a%5E2%2B2a-24+%2B16=0
a%5E2%2B2a-8=0
a+=+%28-2+%2B-+sqrt%28+2%5E2-4%2A1%2A%28-8%29+%29%29%2F%282%2A1%29+
a+=+%28-2+%2B-+sqrt%28+4%2B32+%29%29%2F2+
a+=+%28-2+%2B-+sqrt%28+36+%29%29%2F2+
a+=+%28-2+%2B-+6%29%2F2+
solutions:
a+=+%28-2+%2B+6%29%2F2+
a+=+4%2F2+
highlight%28a+=2%29+
or

a+=+%28-2-+6%29%2F2+
a+=+-8%2F2+
highlight%28a+=-4%29


4.

5y%28y+%2B+6%29+=+4%28y+%2B+6%29...first multiply
5y%5E2+%2B+30+=+4y+%2B+24
5y%5E2+%2B+30+-4y+-24=0
5y%5E2+-4y%2B+6+=0
y+=+%28-%28-4%29+%2B-+sqrt%28+%28-4%29%5E2-4%2A5%2A6+%29%29%2F%282%2A5%29+
y+=+%284+%2B-+sqrt%2816-120+%29%29%2F10+
y+=+%284+%2B-+sqrt%28-104+%29%29%2F10+
y+=+%284+%2B-+sqrt%28%28-1%29104+%29%29%2F10+
y+=+%284+%2B-+i%2Asqrt%28104+%29%29%2F10+
y+=+%284+%2B-+10.2i%29%2F10+
solutions:
y+=+%284+%2B+10.2i%29%2F10+
y+=+4%2F10+%2B+10.2i%2F10+
highlight%28y+=+0.4%2B+1.02i%29+
or
y+=+%284+-+10.2i%29%2F10+
y+=+4%2F10+-+10.2i%2F10+
highlight%28y+=+0.4-+1.02i+%29