Which equation can be used to find the value of b if side a measures 8.7 cm?

Write the sine and cosine values of a, b, respectively, in the figure for (1) and (2) + explanation.

Aright triangle has an area of 21 m2. the dimensions of the triangle are increased by a scale factor of 4. what is the area of the new triangle

Stefanie is painting her bedroom. she can paint 2 1/3 square feet in 4/5 of an hour. how many square feet can she paint in one hour?