Answer:
Area: 60
Step-by-step explanation:
1. Multiply the base and the height which are 12 cm and 10 cm.
2. The multiply that product by 1/2 or you can divide it by 2 to get the area of the triangle.
I don't know what using disk means, sorry but I know that,...
7÷2=3.5
HOPE THIS HELPED :)

cannot be changed to a mixed number. 10 could divide both numerator and denominator. And you get 2.
Yes 1 and 3 are supplementary
Consider right triangles BTZ and BUZ.
ZB = ZB (Common)
ZT = ZU (Given)
Therefore, ΔBTZ ≅ ΔBUZ (By RHS theorem)
Hence, by CPCTC,
∠BTZ = ∠BUZ