Answer:
see explanation
Step-by-step explanation:
Euler's formula states that the sum of the number of faces (F) and the number of vertices (V) of a polyhedra is equivalent to two more than the number of its edges (E) , that is
F + V = E + 2
Answer:
Step-by-step explanation:
Meeting ID: 621 872 6773
Passcode: UL4qmA
Not sure about the first one but the second one is option c (or -3). You just have to factor and find the solutions (so it would be -7 and 4 and then u just add them)
For question 39 the answer is c
Answer:
90 degrees
Step-by-step explanation:
A rhombus has 4 congruent sides, which means that if the cross each crossing part is 90 degrees
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