Answer:
See below.
Step-by-step explanation:
ABC is an isosceles triangle with BA = BC.
That makes angles A and C congruent.
ABD is an isosceles triangle with AB = AD.
That makes angles ABD and ADB congruent.
Since m<ABD = 72 deg, then m<ADB = 72 deg.
Angles ADB and CDB are a linear pair which makes them supplementary.
m<ADB + m<BDC = 180 deg
72 deg + m<BDC = 180 deg
m<CDB = 108 deg
In triangle ABD, the sum of the measures of the angles is 180 deg.
m<A + m<ADB + m<ABD = 180 deg
m<A + 72 deg + 72 deg = 180 deg
m<A = 36 deg
m<C = 36 deg
In triangle BCD, the sum of the measures of the angles is 180 deg.
m<CBD + m<C + m<BDC = 180 deg
m<CBD + 36 deg + 108 deg = 180 deg
m<CBD = 36 deg
In triangle CBD, angles C and CBD measure 36 deg making them congruent.
Opposite sides DB and DC are congruent making triangle BCD isosceles.
Answer:
4
Step-by-step explanation:
Using the Law of Sines (sina/A=sinb/B=sinc/C for any triangle)
sinR/30=sin96/54
sinR=30sin96/54
R=arcsin(30sin96/54)°
R≈33.5° (to nearest tenth of a degree)
I don’t know if this is right but the way I did it I got 7.5
Answer:
28 cm
Step-by-step explanation:
If the shape is a square, all the sides are equal. To find the area you multiply the length by the width. Since the area is 49 centimeters, find the square root of 49 to find the length of the length and the height of the square, which is 7. To find the perimeter, you add the lengths of all the sides of the square. 7+7+7+7=28.