Find Angle DAC in a Deltoid: Using 2x and 60° Relationships

Question

ABCD is a deltoid.

DAC=? ∢DAC=\text{?}

AAABBBCCCDDD2x602x

Video Solution

Step-by-Step Solution

As we know that ABCD is a deltoid, and AC is the bisector of an angle and therefore:

BAC=CAD=2X BAC=CAD=2X

Now we focus on the triangle BAD and calculate the sum of the angles since we know that the sum of the angles in a triangle is 180 degrees:

2X+2X+2X+60=180 2X+2X+2X+60=180

6X+60=180 6X+60=180

18060=6X 180-60=6X

120=6X 120=6X

We divide the two sections by 6:1206=6x6 \frac{120}{6}=\frac{6x}{6}

20=x 20=x

Now we can calculate the angle DAC:

20×2=40 20\times2=40

Answer

30