Let P=(0,0,1),Q=(1,−1,1),R=(−2,1,−1). Find (a) The area of the triangle PQR.

area =

(b) The equation for a plane that contains P, Q, and R.

This plane is

you would need to know all the numbers that are on there

step-by-step explanation:

central angle of a triangle has the same measure as its intercepted arc.

step-by-step explanation:

80° is the measure of gh

step-by-step explanation:

circle f is congruent to circle j

we have two circle with center f and j.

both circles are congruent. the radius of the circle would be equal.

see the attachment for the circle.

we are given ∠efd ≅ ∠gjh

therefore, arc (ed) = arc (gh)     (∴ circle f is congruent to circle j)

but ∠dfe=80°=arc (ed)

therefore, arc (gh) = 80°

thus, 80° is the measure of gh

answer: $1794

step-by-step explanation: