Prove that tan 22.5^circ=sqrt2-1

The distance between the centers of two circles C1 and C2 is equal to 10 cm. The circles have equal radii of 10 cm.

A part of circumference of a circle is called
A. Radius
B. Segment
C. Arc
D. Sector

The perimeter of a basketball court is 108 meters and the length is 6 meters longer than twice the width. What are the length and width?

What are the coordinates of the center and the length of the radius of the circle represented by the equation ${\displaystyle x^2+y^2-4x+8y+11=0}$?

Which of the following pairs of angles are supplementary?
128,62
113,47
154,36
108,72

What is the surface area to volume ratio of a sphere?

An angle which measures 89 degrees is a/an _____.
right angle
acute angle
obtuse angle
straight angle

Herman drew a 4 sided figure which had only one pair of parallel sides. What could this figure be?
Trapezium
Parallelogram
Square
Rectangle

Which quadrilateral has: All sides equal, and opposite angles equal?
Trapezium
Rhombus
Kite
Rectangle

Karen says every equilateral triangle is acute. Is this true?

Find the number of lines of symmetry of a circle.
A. 0
B. 4
C. 2
D. Infinite

The endpoints of a diameter of a circle are located at (5,9) and (11, 17). What is the equation of the circle?

What is the number of lines of symmetry in a scalene triangle?
A. 0
B. 1
C. 2
D. 3

How many diagonals does a rectangle has?

A quadrilateral whose diagonals are unequal, perpendicular and bisect each other is called a.
A. rhombus
B. trapezium
C. parallelogram