Answer:
5 cm
Step-by-step explanation:
We khow that the altitude of this triangle is 1cm shorter than the base
- Let H be our altitude and B our base and A the area of the triangle
- A= (B*H)/2 ⇒ 15=(B*H)/2
- H is 1cm shorter than B ⇒ B=H+1
- H*(H+1)/2=15 ⇒ H*(H+1)=30⇒ H²+H=30⇒H²+H-30+0
that's a quadratic equation . Let's calculate the dicriminant .
Let Δ be the dicriminant
- a=1
- b=1
- c= -30
- Δ=b²-4*a*c = 1²-4*1*(-30)=1+4*30=121≥0
- Δ≥0⇔ that we have two solutions x and y
- x= (-1-
)/2= (-1-11)/2= -6 - y= (-1+)/2= 10/2 = 5
We have a negative value and a positive one
The altitude is a distance so it can't be negative
H= 5cm
The answer is 6 square inches
m GH = 57''
________
tan 39° = opposite / adjacent
tan 39° = m GH / m HJ
tan 39° * m HJ = m GH
m HJ = m GH / tan 39°
m HJ ≈ 57'' / 0.810
m HJ ≈ 70.4'' <——<span>— measure of the segment HJ</span>
________
sin 39° = opposite / hypotenuse
sin 39° = m GH / m GJ
sin 39° * m GJ = m GH
m GJ = m GH / sin 39°
m GJ = 57'' / 0.629
m GJ ≈ 90.6'' <——— measure of the segment GJ
________
So the perimeter is
p = m GH + m HJ + m GJ
p = 57'' + 70.4'' + 90.6''
p = 218'' <——<span>— this is the answer.</span>
I hope this helps. =)
Tags: <em>perimeter right triangle sine cosine tangent sin cos tan trig trigonometry geometry</em>
The value of that is -51. -51 is the answer
