Think & Click: The Algebra o f Parallelograms
Now, you try. Complete the Think & Click activity by looking at each problem below, thinking about it, and then clicking on the question to reveal the solution.
In parallelogram ABCD, the measure of angle DAB equals (5x + 10)°. The measure of angle BCD equals (2x + 19)°. Find the value of x. What is the measure of each angle?
Since the two angles given are opposite, they have equal measure. Set the two expressions equal to each other and solve.
(5x + 10)° = (2x + 19)°
3x = 9
x = 3To find the measure of each angle, substitute this value in for x.
The measure of angle DAB equals 5(3) + 10 = 25°.
The measure of angle BCD equals 2(3) + 19 = 25°.
In parallelogram ABCD, AO = 6y + 2 and AC equals 112. Find the value of y. What is the length of segment AO?
The length of segment AO is half the length of segment AC.
6y + 2 = 56
6y = 54
y = 9To find the length of segment AO, substitute this value in for y.
The length of segment AO equals 6(9) + 2 = 56.
