I have no clue. What is it?
A = w(2w + 3)
90 = 2w^2 + 3w
2w^2 +3w - 90 = 0
(w-6)(2w+15) = 0 (TRINOMIAL FACTORING)
w = 6 inch ( it can't be -15/2 because lengths can't be negative)
l = 2w + 3
= 15 inch
Regular polygon can be incribed in a circle of radius equal to its side.
so if you join all the vertices to the centre, you will get 6 equilateral triangles. each interior angle will have 2 angles of 60 each. thus interior angle = 120
exterior angle=180-120=60
Perpendicular bisectors have a particular property: if AB is a perpendicular bisector of CD, then every point lying on AB has the same distance from C and D.
In your case, we have that every point lying on AC has the same distance from B and D.
So, in particular, we have EB=ED, because E lies on AC.
Moreover, since AC is a perpendicular bisector, it is the height of the triangle (if we choose BD as base), and it bisects BD: this means that the triangle is isosceles, so AD=AB.
This means that triangles ABE and ADE have:
- AD=AB because ABD is isosceles
- EB=ED because AC is the perpendicular bisector of BD
- AE in common
So, their sides are all equal, and thus they are congruent.
