If you could show a picture of the clocks I could help you
I believe the term is "constant".
Part A.
The area of a triangle is given by the product of its base and the height relative to that base.
Since these triangles have the same base b and same height h, they have the same area.
Part B.
The area of a rectangle or parallelogram is given by the product of base and height. Since these figures have the same base and height, they have the same area.
Part C.
These figures have different shapes, so we can't affirm that they have the same area.
Part D.
The height shown in the image is not the height relative to side b, therefore we can't affirm that the triangles have the same area.
You would have to make common denominators
consider a/b,c/d in Q
then a/b - c/d = ad/db - cb/bd = (ad-cb)/db for all a,b,c,d in R, exclude b,d=0
i.e. 1/2 - 1/4
=4/8 - 2/8 =(4-2)/8=2/8 =1/4
first off, make sure you have a Unit Circle, if you don't do get one, you'll need it, you can find many online.
let's double up 67.5°, that way we can use the half-angle identity for the cosine of it, so hmmm twice 67.5 is simply 135°, keeping in mind that 135° is really 90° + 45°, and that whilst 135° is on the 2nd Quadrant and its cosine is negative 67.5° is on the 1st Quadrant where cosine is positive, so
![cos(\alpha + \beta)= cos(\alpha)cos(\beta)- sin(\alpha)sin(\beta) \\\\\\ cos\left(\cfrac{\theta}{2}\right)=\pm \sqrt{\cfrac{1+cos(\theta)}{2}} \\\\[-0.35em] ~\dotfill\\\\ cos(135^o)\implies cos(90^o+45^o)\implies cos(90^o)cos(45^o)~~ - ~~sin(90^o)sin(45^o) \\\\\\ \left( 0 \right)\left( \cfrac{\sqrt{2}}{2} \right)~~ - ~~\left( 1\right)\left( \cfrac{\sqrt{2}}{2} \right)\implies -\cfrac{\sqrt{2}}{2} \\\\[-0.35em] ~\dotfill](https://tex.z-dn.net/?f=cos%28%5Calpha%20%2B%20%5Cbeta%29%3D%20cos%28%5Calpha%29cos%28%5Cbeta%29-%20sin%28%5Calpha%29sin%28%5Cbeta%29%20%5C%5C%5C%5C%5C%5C%20cos%5Cleft%28%5Ccfrac%7B%5Ctheta%7D%7B2%7D%5Cright%29%3D%5Cpm%20%5Csqrt%7B%5Ccfrac%7B1%2Bcos%28%5Ctheta%29%7D%7B2%7D%7D%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill%5C%5C%5C%5C%20cos%28135%5Eo%29%5Cimplies%20cos%2890%5Eo%2B45%5Eo%29%5Cimplies%20cos%2890%5Eo%29cos%2845%5Eo%29~~%20-%20~~sin%2890%5Eo%29sin%2845%5Eo%29%20%5C%5C%5C%5C%5C%5C%20%5Cleft%28%200%20%5Cright%29%5Cleft%28%20%5Ccfrac%7B%5Csqrt%7B2%7D%7D%7B2%7D%20%5Cright%29~~%20-%20~~%5Cleft%28%201%5Cright%29%5Cleft%28%20%5Ccfrac%7B%5Csqrt%7B2%7D%7D%7B2%7D%20%5Cright%29%5Cimplies%20-%5Ccfrac%7B%5Csqrt%7B2%7D%7D%7B2%7D%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill)
