i think that you are multiplying them so the answer is 3553.5
and if your adding it would be 122.1
 
        
             
        
        
        
Answer:
Triangle Sum Theory
Step-by-step explanation:
You add all the angles to get 180
 
        
                    
             
        
        
        
Answer:
6.86
Step-by-step explanation:
 
        
             
        
        
        
The given angles are complementary, therefore:
(5r + 5) + (8r -6) = 90°
13r - 1 = 90 
13r - 1 + 1 = 90 + 1
13r = 91
13r/13 = 91/13
r = 7
        
             
        
        
        
Given : In Right triangle ABC, AC=6 cm, BC=8 cm.Point M and N belong to AB so that AM:MN:NB=1:2.5:1.5.
To find : Area (ΔMNC)
Solution: In Δ ABC, right angled at C,
AC= 6 cm, BC= 8 cm
Using pythagoras theorem
AB² =AC²+ BC²
       =6²+8²
      = 36 + 64
 →AB²  =100
→AB²  =10²
  →AB  =10
Also, AM:MN:NB=1:2.5:1.5
Then AM, MN, NB are k, 2.5 k, 1.5 k.
→2.5 k + k+1.5 k= 10
→ 5 k =10
Dividing both sides by 2, we get
→ k =2
MN=2.5×2=5 cm, NB=1.5×2=3 cm, AM=2 cm
As Δ ACB and ΔMNC are similar by SAS.
So when triangles are similar , their sides are proportional and ratio of their areas is equal to square of their corresponding sides.
![\frac{Ar(ACB)}{Ar(MNC)}=[\frac{10}{5}]^{2}](https://tex.z-dn.net/?f=%5Cfrac%7BAr%28ACB%29%7D%7BAr%28MNC%29%7D%3D%5B%5Cfrac%7B10%7D%7B5%7D%5D%5E%7B2%7D)

But Area (ΔACB)=1/2×6×8= 24 cm²[ACB is a right angled triangle]

→ Area(ΔMNC)=24÷4
→Area(ΔMNC)=6 cm²