Question

Help please! I have choral practice...

Answer 1

Slice the picture in half, across the middle dotted line.

The top half is a triangle. Its base is 15cm and its height is 8cm .
Area of a triangle is (1/2) (base x height) = (1/2) (120cm²) = 60 cm².

The bottom half is a parallelogram. Its base is 15cm and its height is 5cm.
Area of a parallelogram is (base x height) = (15cm x 5cm) = 75 cm².

Add the two pieces together. (60cm²) + (75 cm²) = 135 cm²

Breathe from the diaphragm, enunciate, and watch the conductor.

Answer 2

This polygon is composed of a right triangle and a parallelogram.

The area of right angle :

`A_\Delta=(1)/(2)\cdot15\cdot8=(1)/(2)\cdot120=\boxed{60\ (cm^2)}`

The area of the parallelogram:

`A_P=15\cdot(13-8)=15\cdot5=\boxed{75\ (cm^2)}`

The area of the polygon is equal:
`A=A_\Delta+A_P`

Therefore, the answer is:

`\boxed{\boxed{A=60\ cm^2+75\ cm^2=135\ cm^2}}`