Question

Plss help me quickly tyyyeither question 5 or six cus I need the explanation:)))​

Answer 1

Find FM using Pythagoras Theorem:

We're not after c^2 using pythag - rearrange it:

It don't matter were the B or A is in the equation - it'll give u the missing length you're after.

c^2 - b^2 = a^2

8^2 - 5^2 = a^2

Square root both sides to get A on its own

A= root 8^2 - 5^2

= root 39

= 6.24499....

Or

6.24cm, but FM is root 39 I'll use throughout, even if I use 6.24 in calculations, it's to make things clearer for you.

Create diagonal line from B to E - drawing right-angle triangle A to B to E back to A.

AB is 16cm

AE is 8cm - given above

(because the triangle at the front & back are the same.)

Use Pythagoras Theorem for length BE:

a^2 + b^2 = c^2

16^2 + 8^2 = c^2

Square root

C = root 16^2 + 8^2

= 8 root 5

= 17.8885...

8 Square root 5 - I'll use for BE

Creat another triangle to find the angel -

B to E to (M between the length AD)

However, diagonal line B to M needed.

So, m is the mid-point of the base triangle, pretend to slice it in half from point M - this creates a mini rectangle. (ABM to MA - with M on side AD)

Now use this to find B to M:

(if MC is 5cm, BM is 5cm - on length BC)

C = root 16^2 + 5^2

= root 281

= 16.76305...

= 16.76

Create right-angle triangle:

Be to M back to B

BE= 8 root 5

EM = root 39

MB = root 281

So, the angle will be from EB to M.

EB is the hypotenuse

BM is the adjacent

AH means Cah, but the inverse

Cos-1(a/h)

Cos-1(root 281 / 8 root5) = 20.4326...

Thus, angle we're after is 20.43 degrees to 2.dp

(The easiest way for me to explain - it took a while)

Hope this helps!