What are m21 and m_2?

<1  = 35degrees

<2  = 30degrees

Step-by-step explanation:

Using the theorem that the sum of external angle is equal to sum of interior angle

Considering the smaller triangle

Exterior angle = 115 degrees

Sum of interior = <1 + 80

Equating both

<1 + 80 = 115

<1 = 115 - 80

<1  = 35degrees

For the big rectangle

Exterior angle = 115 degrees

Sum of interior = <2 + 85

Equating both

<2 + 85 = 115

<2 = 115 - 85

<2 = 30degrees

3. parallelogram

step-by-step explanation:

we turn each of our sides into direction vectors

ab=b-a=(3 - 7, 1 - 0) = (-4, 1)

bc=c-b=(1,6)

cd=d-c=(4,-1)

da=a-d=(-1,-6)

we see how the opposite sides have negated direction vectors; this is characteristic of a parallelogram.   we have congruent sides ab=cd and bc=da with unequal lengths because 1^2+6^2 is different from (-4)^2+1^2.   so it's not a square or a rhombus.  

we check the dot product of direction vectors of adjacent sides.   we have

ab dot bc = -4(1) + 1(6) = 2

that's not zero so the sides are not perpendicular.   we've ruled out rectangle.

the direction vectors indicate two pairs of congruent parallel sides, so we choose parallelogram over trapezoid.

b

step-by-step explanation: