Ernest built an access ramp to his house. It has a horizontal length of 8 feet, a vertical height of 3.9 feet, and the length of the ramp is 8.9 feet. Is the statement true or false? The ramp is perfectly square.

1. \( \triangle A B C \) is right angled at \( A \). \( A D \) is perpendicular to \( B C \). If \( A B=8 \mathrm{~cm}, B C=10 \mathrm{~cm} \) and \( A C=6 \mathrm{~cm} \). Find the area of \( \triangle A B C \). Also, find the length of \( A D \).

Si el perímetro de un círculo es \( 10 \pi \mathrm{~cm} \). ¿cuál es el área de su semicirculo?

An equilateral triangle it's perimeter equals 27 cm , then it's side length is......

9. In the given figure \( D L \) and \( B M \) are the heights corresponding to sides \( A B \) and \( A D \) respectively of parallelogram \( A B C D \). If the area of parallelogram is \( 300 \mathrm{~cm}^{2}, A B=30 \mathrm{~cm} \) and \( A D=20 \mathrm{~cm} \). Find the length of \( B M \) and \( D L \).

3.4.1 What type is triangle \( A B C \) ?