Which product is undefined? A. HK, where H is a 3 x 3 matrix and Kis a 3 x 1 matrix
B. AB, where A is a 3 x 2 matrix and Bis a 3 x 1 matrix
C. CD, where Cis a 3 x 1 matrix and D is a 1x 2 matrix
D. NP, where N is a 2 x 1 matrix and Pis a 1x 4 matrix

step-by-step explanation:

de-gf

hj=3x+20

ji=15x-64

0,0

step-by-step explanation:

1. 180°. the sum of the interior angles of a triangle is 180°, for the equilateral triangle that it has three equals side is 60°+60°+60°=180°.

2. 60°. each interior angle of a equilateral triangle is 60°

3. 120°. the measure of ∠m is 120°, the sum of the angles ∠m and ∠n is equal to 180°. so, in order to find the measure of ∠m, we have ∠m+∠n=180° > ∠m=180°-∠n > ∠m=180°-60°=120°.

4. 360°. the sum of the exterior angles of an equilateral triangle is ∠m+∠r+∠x=120°+120°+120°=360°. the exterior angles of any triangle always add 360°.