Question

1. perimeter (terms of pi) __ perimeter (number) __

Explanation:

Step1: Identify straight - line segments

The straight - line segments are two 10 cm segments and one 7 cm segment. The sum of the lengths of the straight - line segments is $10 + 10+7=27$ cm.

Step2: Identify curved part

The curved part is a semi - circle. The diameter of the semi - circle is 4 cm, so the circumference of the semi - circle is $\frac{1}{2}\times\pi\times d=\frac{1}{2}\times\pi\times4 = 2\pi$ cm.

Step3: Calculate perimeter in terms of $\pi$

The perimeter $P$ in terms of $\pi$ is the sum of the lengths of the straight - line segments and the semi - circular arc. So $P = 27+2\pi$ cm.

Step4: Calculate perimeter as a number

Taking $\pi\approx3.14$, we have $P=27 + 2\times3.14=27+6.28 = 33.28$ cm.

Answer:

Perimeter (terms of Pi): $27 + 2\pi$ cm
Perimeter (number): $33.28$ cm