Measuring 2D figures Flashcards
What is the formula for the area of a triangle?
A=1/2bh where b is base and h is height perpendicular to the base
What is the perimeter of a polygon?
Simply the sum of the lengths of all sides
What is the Pythagorean theorem?
a^2 + b^2= c^2.
A = height B= base C= hypotenuse
This only works for right triangles
What is a Pythagorean triple?
Set of three positive integers that satisfy the Pythagorean theorem.
3-4-5, 6-8-10, 9-12-15, 8-15-17
What is a trig function?
It relates the sides of a right triangle to one of its angle measures. The three basic function are sine, cosine, tangent
What is the sine of an angle?
The ratio of the length opposite the angle to the hypotenuse
Sin A= side opposite A/hypotenuse
What is the cosine if an angle?
The ratio of the length of the leg adjacent to the angle to the hypotenuse
Cos A = side adjacent to A/hypotenuse
What is the tangent of an angle?
The ratio of the length of the leg opposite the angle to the side adjacent to the angle
Tan A = side opposite A/ side adjacent to A
What is the equation for finding the area of quadrilaterals?
A= bh
*base and height must be perpendicular
What is the equation for finding the area of a trapezoid?
A= 1/2h(b1 + b2)
*b1 and b2 are parallel bases and h is perpendicular
What is the radius of a circle?
A segment that joins the center of the circle to any point along the perimeter
What is the diameter?
A segment that contains the center of the circle and whose endpoints lie on the circle
What is the formula for the circumference of a circle?
C= 2 pi r (radius) C= pi d (diameter)
What is the equation for finding the area of a circle?
A = pi r^2
Triangle’s Altitude
A line dropped from tee apex of a triangle perpendicular to the base forming a right angle
