Problem 1
Answers:
angle 6 = 50
angle 7 = 50
angle 8 = 40
--------------------
Work Shown:
point E = intersection point of diagonals.
x = measure of angle 6
y = measure of angle 8
angle 7 is also x because triangle AED is isosceles (AE = ED)
Focus on triangle AED, the three angles A, E, D add to 180
A+E+D = 180
x+80+x = 180
2x+80 = 180
2x = 180-80
2x = 100
x = 100/2
x = 50
So both angles 6 and 7 are 50 degrees.
Turn to angle 8. This is adjacent to angle 7. The two angles form a 90 degree angle at point A. This is because a rectangle has 4 right angles.
(angle7)+(angle8) = 90
50+y = 90
y = 90-50
y = 40
angle 8 = 40 degrees
=================================================
Problem 2
Answers:
angle 2 = 61
angle 3 = 61
--------------------
Work Shown:
Angle 5 is 29 degrees (given). So is angle 4 because these are the base angles of isosceles triangle DEC (segment DE = segment EC)
angle 3 and angle 4 form a 90 degree angle
x = measure of angle 3
(angle 3)+(angle 4) = 90
x+29 = 90
x = 90-29
x = 61
Angle 2 is congruent to angle 3 since triangle BEC is isosceles (BE = EC), so both angle 2 and angle 3 are 61 degrees each.
