9. Justify the following statement using an algebraic proof: In a triangle, if the sum of the measures of two angles is equal to the measure of the third angle, then the triangle is a right triangle. statements? reasons?

Question

9.	Justify the following statement using an algebraic proof: In a triangle, if the sum of the measures of two angles is equal to the measure of the third angle, then the triangle is a right triangle.  statements? reasons?

anonymous · Answer

let 3 angles be x,y,z
x + y = z  so:
x + y - z = 0
x + y + z = 180
subtract
-2z = -180
z = 90
so triangle is right-angled

anonymous · Answer

do u follow that ok?

anonymous · Answer

i think i can figure it out a little better now, thank you. the only thing that confuses me is its one of those chart things that have statements/reasons so i need to write down the reasons

anonymous · Answer

ok well reason for x+y+z = 180 is  3 angles of triangle add up to 180 degrees
- excuse me if u knew that already!

anonymous · Answer

yeah its alright though! it helped a lot!

anonymous · Answer

good