Chapter Review
Sign In
If a parallelogram is a rectangle, then its diagonals are congruent.
m ∠ 1= 124
m ∠ 2 = 28
m ∠ 3 =62
The given parallelogram is a rectangle, as its opposite sides are parallel and one of its angles is right. Let's find the measure of each numbered angle one at a time.
We see that ∠ 1 and the angle with measure 56^(∘) form a linear pair. Therefore, we can conclude that their measures add to 180. m ∠ 1 + 56 =180 ⇔ m ∠ 1 =124
m ∠ 3'= m ∠ 3
Add terms
LHS-56=RHS-56
.LHS /2.=.RHS /2.
In a rectangle all angles are right and have the measure 90. Therefore, m∠ 2 and m∠ 3 must add to 90. m∠ 2 + m∠ 3=90 Let's substitute 62 for m∠ 3 and solve for m ∠ 2. m∠ 2 + 62=90 ⇔ m ∠ 2 = 28 Therefore, the measure of ∠ 2 is 28.