Geometry Flashcards
Area of a triangle?
A=(1/2)bh
What are complimentary angles?
They add to equal 90°.
What are supplementary angles?
They add to equal 180°.
How do you set up sine equations?
Sin x°=opposite/hypotenuse
How do you set up cosine equations?
cos x°=adjacent/hypotenuse
How do you set up tangent equations?
tan x°=opposite/adjacent
When do you use the inverse sin/cos/tan feature on your calculator? (e.g. Sin^-1)
ONLY when solving for an angle measure.
Area of a circle?
A=πr² (r is radius)
Circumference of a circle?
C=2πr
Area of a sector?
A=πr²•(degree measure of sector/360°)
The degree measure of the sector describes what fraction of the circle it is.
Length of an arc?
C= 2πr•(degree measure of arc/360°)
How do you find the measure of an inscribed angle?
The inscribed angle is equal to 1/2 of its intercepted arc.
Do inscribed angles with the same intercepted arc have the same angle measure?
Yes.
What’s an inscribed angle?
An angle inside a circle. The vertex of the angle must touch the circumference of the circle.
What do we know about a right triangle inscribed in a circle?
The hypotenuse is the diameter of the circle. SO, if a triangle is inscribed in a circle and one side of the triangle is a diameter - the triangle is a right triangle.
