39×2÷6=13
13-5=8 mm. The other base of the trapezoid is 8 mm. Let check it:
1/2(8+5)×6
=1/2×13×6
=39 square mm. Hope it help!
Answer:
B
Step-by-step explanation:
The two triangles are congruent because they have three rispective side congruent
AB and AD are both radiuses and AC is in common
so m arc BC is 78 degrees
Just draw three rectangles and a half of one