<h2>
Explanation:</h2>
In every rectangle, the two diagonals have the same length. If a quadrilateral's diagonals have the same length, that doesn't mean it has to be a rectangle, but if a parallelogram's diagonals have the same length, then it's definitely a rectangle.
So first of all, let's prove this is a parallelogram. The basic definition of a parallelogram is that it is a quadrilateral where both pairs of opposite sides are parallel.
So let's name the vertices as:

First pair of opposite sides:
<u>Slope:</u>

Second pair of opposite sides:
<u>Slope:</u>

So in fact this is a parallelogram. The other thing we need to prove is that the diagonals measure the same. Using distance formula:

So the diagonals measure the same, therefore this is a rectangle.
The inscribed angle is always half of the central angle.
So 60÷2=30
Answer:
Step-by-step explanation:
I believe that this is the answer.
Answer:
x = 110°
Step-by-step explanation:
The Outside Angle Theorem states that the measure of the angle formed by two secants or a secant and tangent from a point outside of a circle is half the difference between the two arcs.
This means that ½ (210 – x) = 50.
½ ( 210 – x ) × 2 = 50 × 2
210 – x = 100.
210 – x + x = 100 + x.
210 = 100 + x.
100 + x = 210.
100 + x – 100 = 210 – 100.
x = 110.
This value must be true because:
½ ( 210 – 110 ) = 50.
½ ( 100 ) = 50.
50 = 50.
Answer:
3+5(9+2)= 48+5b true true